How do I get coc.nvim to auto-open?

Question

I installed

Plug 'neoclide/coc.nvim', {'branch': 'release'}

And now I seem to be able to use <C-n> and <C-p> to trigger autocomplete menu but it doesn't show up automatically as I type.

I tried adding

Plug 'vim-scripts/AutoComplPop'

but that does not seem to do anything.

My complete config is

set list
set listchars=tab:\\t
" For Vundle
set shell=/bin/bash
"set shell=bash
hi SpecialKey   guifg=#DD0000
hi SpecialKey   ctermfg=9
set nocompatible              " be iMproved, required
filetype off                  " required
" don't give message when an existing swap file is found.
set shortmess+=A
"https://stackoverflow.com/questions/1269689/to-disable-entering-ex-mode-in-vim
map Q <Nop>
" enforce soft tabs
set tabstop=2
set softtabstop=2
set shiftwidth=2
set expandtab
"grep -rl FactoryBot.create spec | xargs sed -i 's/FactoryBot.create/create/g'
"au! FileType ruby set tabstop=2 softtabstop=2 shiftwidth=2 expandtab
"au! FileType rb set tabstop=2 softtabstop=2 shiftwidth=2 expandtab
"au! FileType js set tabstop=2 softtabstop=2 shiftwidth=2 expandtab
"au! FileType jsx set tabstop=2 softtabstop=2 shiftwidth=2 expandtab
"au! FileType css set tabstop=2 softtabstop=2 shiftwidth=2 expandtab
"au! FileType scss set tabstop=2 softtabstop=2 shiftwidth=2 expandtab
" no line numbers to conserve space
set nonu
set ruler
"set rulerformat=%l,%v
set rulerformat=%-14.(%l,%c%V%)\ %P
set termguicolors
let $NVIM_TUI_ENABLE_TRUE_COLOR=1
"faster update time for git gutter
set updatetime=100
" Specify a directory for plugins (for Neovim: ~/.local/share/nvim/plugged)
call plug#begin('~/.vim/plugged')
Plug 'neoclide/coc.nvim', {'branch': 'release'}
set signcolumn=yes
inoremap <silent><expr> <TAB>
      \ coc#pum#visible() ? coc#pum#next(1) :
      \ CheckBackspace() ? "&lt;Tab>" :
      \ coc#refresh()
inoremap <expr><S-TAB> coc#pum#visible() ? coc#pum#prev(1) : "&lt;C-h>"
inoremap <silent><expr> <CR> coc#pum#visible() ? coc#pum#confirm()
                              : "&lt;C-g>u&lt;CR>&lt;c-r>=coc#on_enter()&lt;CR>"
nmap <silent> gd <Plug>(coc-definition)
nmap <silent> gy <Plug>(coc-type-definition)
nmap <silent> gi <Plug>(coc-implementation)
nmap <silent> gr <Plug>(coc-references)
nnoremap <silent> K :call ShowDocumentation()<CR>
function! ShowDocumentation()
  if CocAction('hasProvider', 'hover')
    call CocActionAsync('doHover')
  else
    call feedkeys('K', 'in')
  endif
endfunction
Plug 'vim-scripts/AutoComplPop'
" vim in chrome / FF
"Plug 'glacambre/firenvim', { 'do': { _ -> firenvim#install(0) } }
" remove highlight when moving away from a highlight
Plug 'jesseleite/vim-noh'
" rip and tear through files at lightning speed
Plug 'jremmen/vim-ripgrep'
nnoremap ss :Rg 
nnoremap ss :Rg
Plug 'hwartig/vim-seeing-is-believing'
" better python highlighting
"Plug 'numirias/semshi', {'do': ':UpdateRemotePlugins'}
" fast than vimgrep, similar syntax
" :Ack FactoryBot.create spec
"Plugin 'mileszs/ack.vim'
"if exists('g:started_by_firenvim')
"endif
" Make sure you use single quotes
"Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins' }
"Plug 'ervandew/supertab'
"Plug 'elmcast/elm-vim'
"Plug 'yuezk/vim-js'
"Plug 'maxmellon/vim-jsx-pretty'
"Plug 'pangloss/vim-javascript', { 'for': ['javascript', 'javascript.jsx'] }
"Plug 'mxw/vim-jsx', { 'for': ['javascript', 'javascript.jsx'] }
Plug 'sheerun/vim-polyglot'
"Plug 'camspiers/lens.vim'
Plug 'git@github.com:habamax/lens.vim.git', { 'as': 'camspiers-habamax', 'branch': 'fix-resize' }
"Plug 'dkprice/vim-easygrep'
Plug 'wincent/ferret'
let g:lens#width_resize_max = 100
let g:lens#width_resize_min = 10
let g:lens#animate = 0
Plug 'rust-lang/rust.vim'
let g:rust_recommended_style = 0
Plug 'voldikss/vim-floaterm'
"let g:floaterm_keymap_new    = '<F7>'
"let g:floaterm_keymap_prev   = '<F8>'
"let g:floaterm_keymap_next   = '<F9>'
let g:floaterm_keymap_toggle = '<Caps>'
let g:floaterm_position = 'center'
let g:floaterm_width = 0.9
let g:floaterm_height = 0.9
Plug 'cespare/vim-toml'
Plug 'jceb/vim-orgmode'
Plug 'airblade/vim-gitgutter'
"Plug 'gabrielelana/vim-markdown' "nice syntax, slow spell checker
Plug 'yegappan/mru'
"Plug 'SirVer/ultisnips'
"Plug 'honza/vim-snippets'
"Plug 'ternjs/tern_for_vim', { 'for': ['javascript', 'javascript.jsx'] }
"Plug 'carlitux/deoplete-ternjs', { 'for': ['javascript', 'javascript.jsx'] }
"Plug 'othree/jspc.vim', { 'for': ['javascript', 'javascript.jsx'] }
Plug 'prakashdanish/vim-githubinator'
Plug 'Konfekt/vim-scratchpad'
Plug 'tpope/vim-fugitive'
Plug 'Wolfy87/vim-syntax-expand'
Plug 'keith/rspec.vim'
"Plug 'TaDaa/vimade'
"
Plug 'vimwiki/vimwiki'
" TODO set subdirectory based on current project directory
" this could be done when a new file is opened(?) or on a load
let g:vimwiki_list = [{'path': '~/wiki/hs-tasks'}]
"let g:vimwiki_folding = 'expr'
" Set specific linters
let g:ale_linters = {
\   'javascript': ['eslint'],
\   'ruby': ['rubocop'],
\   'python': ['pylint'] 
}
"let g:airline#extensions#ale#enabled = 1 
"Plug 'vim-airline/vim-airline-themes'
let g:ale_fixers = {
\   'ruby': ['rubocop', 'trim_whitespace'],
}
if exists('g:started_by_firenvim')
else
  " Linting / rubocop
  Plug 'w0rp/ale'
  Plug 'vim-airline/vim-airline'
let g:airline#extensions#ale#enabled = 1 
  Plug 'vim-airline/vim-airline-themes'
  "set laststatus=2
let g:airline_section_a = ''
  let g:airline_section_b = ''
let g:airline_section_x = ''
  let g:airline_section_y = ''
  "let g:airline_section_z = ''
  "let g:airline_section_z = '%3p%% %3l/%L:%3v'
  let g:airline_section_z = '%l:%v'
let g:airline_theme='hybrid'
endif
" Use release branch (Recommend)
Plug 'neoclide/coc.nvim', {'branch': 'release'}
"inoremap <silent><expr> <TAB>
      "\ pumvisible() ? "&lt;C-n>" :
      "\ <SID>check_back_space() ? "&lt;TAB>" :
      "\ coc#refresh()
"inoremap <expr><S-TAB> pumvisible() ? "&lt;C-p>" : "&lt;C-h>"
"function! s:check_back_space() abort
  "let col = col('.') - 1
  "return !col || getline('.')[col - 1]  =~# '\s'
"endfunction
inoremap <silent><expr> <TAB>
      \ pumvisible() ? "&lt;C-n>" :
      \ <SID>check_back_space() ? "&lt;TAB>" :
      \ coc#refresh()
inoremap <expr><S-TAB> pumvisible() ? "&lt;C-p>" : "&lt;C-h>"
function! s:check_back_space() abort
  let col = col('.') - 1
  return !col || getline('.')[col - 1]  =~# '\s'
endfunction
Plug 'scrooloose/nerdcommenter'
nmap // <leader>c<space>
vmap // <leader>c<space><cr>gv
nnoremap qq :q!<cr>
nnoremap qqa :qa!<cr>
nnoremap ffs :<C-f>/
"nnoremap <leader>ppj :%!python -m json.tool<CR>
"nnoremap <leader>ppj :%!python -c "import json, sys, collections; print json.dumps(json.load(sys.stdin, object_pairs_hook=collections.OrderedDict), indent=2)"<CR>
nnoremap <leader>ppj :%!python -c "import json, sys, collections; print json.dumps(json.load(sys.stdin), indent=2)"<CR>
vnoremap <leader>ppj :%!python -c "import json, sys, collections; print json.dumps(json.load(sys.stdin), indent=2)"<CR>
Plug 'sbdchd/neoformat'
nnoremap <leader>f :Neoformat! html<cr>
Plug 'junegunn/fzf', { 'do': './install --bin' }
Plug 'junegunn/fzf.vim'
" https://github.com/junegunn/fzf.vim/issues/439
"Plug 'junegunn/fzf', { 'dir': '/home/linuxbrew/.linuxbrew/bin' }
"Plug 'junegunn/fzf.vim'
let g:fzf_command_prefix = 'Fzf'
nnoremap <C-p> :FzfGFiles<CR>
" should help with slow Fzf cancel
if has('nvim')
  aug fzf_setup
    au!
    au TermOpen term://*FZF tnoremap <silent> <buffer><nowait> <esc> <c-c>
  aug END
end
" Initialize plugin system
call plug#end()
let g:deoplete#enable_at_startup = 1
" set the runtime path to include Vundle and initialize
set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()
" alternatively, pass a path where Vundle should install plugins
"call vundle#begin('~/some/path/here')
" let Vundle manage Vundle, required
Plugin 'VundleVim/Vundle.vim'
Plugin 'slim-template/vim-slim.git'
" Plugin 'ntpeters/vim-better-whitespace'
Plugin 'scrooloose/nerdtree'
Plugin 'vim-ruby/vim-ruby'
"let strip_whitespace_on_save = 1
Plugin 'kchmck/vim-coffee-script'
" loks nice, has bright theme but does not work
"Plugin 'sonph/onehalf', {'rtp': 'vim/'}
"Plugin 'hakunin/StripWhiteSpaces'
"Plugin 'vim-scripts/ctrlp.vim'
" Matcher needs to be built :/
" ideally I want something that works out of the box
"Plugin 'JazzCore/ctrlp-cmatcher'
"let g:ctrlp_match_func = {'match' : 'matcher#cmatch' }
"Plugin 'syntastic'
"Plugin 'vim-wakatime'
" Didn't work well after reinstall on Fedora
"Plugin 'pangloss/vim-javascript'
"Plugin 'mxw/vim-jsx'
let g:jsx_ext_required = 0
"Plugin 'elixir-lang/vim-elixir'
"Plugin 'floobits/floobits-neovim'
"Plugin 'kana/vim-submode'
"https://vi.stackexchange.com/questions/3728/how-can-i-work-with-splits-in-vim-without-ctrl-w
"does not seem to work with neovim
"call submode#enter_with('WindowsMode', 'n', '', '<Leader>k', ':echo "windows mode"<CR>')
"call submode#leave_with('WindowsMode', 'n', '', '<Leader>')
" Change of windows with hjkl
"call submode#map('WindowsMode', 'n', '', 'j', '<C-w>j')
"call submode#map('WindowsMode', 'n', '', 'k', '<C-w>k')
"call submode#map('WindowsMode', 'n', '', 'h', '<C-w>h')
"call submode#map('WindowsMode', 'n', '', 'l', '<C-w>l')
" split windows with / and !
"call submode#map('WindowsMode', 'n', '', '"', '<C-w>s')
"call submode#map('WindowsMode', 'n', '', '%', '<C-w>v')
"call submode#map('WindowsMode', 'n', '', 'q', '<C-w>c')
"call submode#map('WindowsMode', 'n', '', '<C-j>', '<C-w>J')
"call submode#map('WindowsMode', 'n', '', '<C-k>', '<C-w>K')
"call submode#map('WindowsMode', 'n', '', '<C-h>', '<C-w>H')
"call submode#map('WindowsMode', 'n', '', '<C-l>', '<C-w>L')
"Plugin 'rust-lang/rust.vim'
"Plugin 'Valloric/YouCompleteMe'
"let g:ycm_min_num_of_chars_for_completion = 1
"
"Plugin 'vim-scripts/vim-auto-save'
"let g:auto_save = 1  " enable AutoSave on Vim startup
set undodir=~/.vim/undodir
set undofile
set undolevels=5000
set undoreload=10000
" viminfo stores the the state of your previous editing session
"set viminfo+=n~/.vim/viminfo
"set viminfo+=n~/.vim/viminfo
if exists("+undofile")
  " undofile - This allows you to use undos after exiting and restarting
  " This, like swap and backup files, uses .vim-undo first, then ~/.vim/undo
  " :help undo-persistence
  " This is only present in 7.3+
  if isdirectory('~/.vim/undo') == 0
    :silent !mkdir -p ~/.vim/undo > /dev/null 2>&1
  endif
  set undodir=./.vim-undo//
  set undodir+=~/.vim/undo//
  set undofile
endif
"set directory=~/.vim/swapfiles//
" Save your backup files to a less annoying place than the current directory.
" If you have .vim-backup in the current directory, it'll use that.
" Otherwise it saves it to ~/.vim/backup or .
if isdirectory($HOME . '/.vim/backup') == 0
  :silent !mkdir -p ~/.vim/backup >/dev/null 2>&1
endif
set backupdir-=.
set backupdir+=.
set backupdir-=~/
set backupdir^=~/.vim/backup/
set backupdir^=./.vim-backup/
set backup
" Save your swap files to a less annoying place than the current directory.
" If you have .vim-swap in the current directory, it'll use that.
" Otherwise it saves it to ~/.vim/swap, ~/tmp or .
if isdirectory($HOME . '/.vim/swap') == 0
  :silent !mkdir -p ~/.vim/swap >/dev/null 2>&1
endif
set directory=./.vim-swap//
set directory+=~/.vim/swap//
set directory+=~/tmp//
set directory+=.
syntax on
"au BufRead,BufNewFile .tr set filetype=rust
au BufRead,BufNewFile .thor set filetype=ruby
au BufRead,BufNewFile Gemfile.local set filetype=ruby
" uses old regex engine that is faster with ruby files
" http://stackoverflow.com/questions/16902317/vim-slow-with-ruby-syntax-highlighting
"set re=1
" this could improve vim speed overall
set ttyfast
set lazyredraw
" automaticaly reload files when they're changed without asking
"set autoread
let g:vimrubocop_config = '~/.vim/rubocop.yml'
set packpath^=~/.vim
set runtimepath^=~/.vim
execute pathogen#infect()
"filetype plugin indent on
"for ctrlP
"set runtimepath^=~/.vim/bundle/ctrlp.vim
"let g:ctrlp_user_command = ['.git/', 'git --git-dir=%s/.git ls-files -oc --exclude-standard']
"let g:ctrlp_user_command = ['.git/', 'git --work-tree=%s ls-files -oc --exclude-standard']
"let g:ctrlp_working_path_mode = 'ra'
" 'r' stands for go down until you hit .git
"let g:ctrlp_working_path_mode = 'a'
"let g:ctrlp_custom_ignore = {
  "\ 'dir': 'node_modules|DS_Store|.git|tmp'
  "\ }
"'g:ctrlp_switch_buffer'
"When opening a file, if it's already open in a window somewhere, CtrlP will try
"to jump to it instead of opening a new instance: >
"  let g:ctrlp_switch_buffer = 'Et'
"<
"  e - jump when <cr> is pressed, but only to windows in the current tab.
"  t - jump when <c-t> is pressed, but only to windows in another tab.
"  v - like "e", but jump when <c-v> is pressed.
"  h - like "e", but jump when <c-x> is pressed.
"  E, T, V, H - like "e", "t", "v", and "h", but jump to windows anywhere.
"  0 or <empty> - disable this feature.
"When opening a file with <cr>, CtrlP avoids opening it in windows created by
"plugins, help and quickfix. Use this to setup some exceptions: >
"let g:ctrlp_reuse_window = 'nerdtree'
" https://github.com/kien/ctrlp.vim/issues/305
" CtrlP auto cache clearing.
" ----------------------------------------------------------------------------
"function! SetupCtrlP()
  "if exists("g:loaded_ctrlp") && g:loaded_ctrlp
    "augroup CtrlPExtension
      "autocmd!
      "autocmd FocusGained  * CtrlPClearCache
      "autocmd BufWritePost * CtrlPClearCache
    "augroup END
  "endif
"endfunction
"if has("autocmd")
  "autocmd VimEnter * :call SetupCtrlP()
"endif
set wildignore+=node_modules/**
set wildignore+=tmp/cache/**
set wildignore+=/coverage/
set wildignore+=*/testxml
"set nobackup
"set nowritebackup
"set noswapfile
set guioptions-=m  "remove menu bar
set guioptions-=T  "remove toolbar
map <C-k> <C-w><Up>
map <C-j> <C-w><Down>
map <C-l> <C-w><Right>
map <C-h> <C-w><Left>
nnoremap K <C-w><Up>
nnoremap J <C-w><Down>
nnoremap L <C-w><Right>
nnoremap H <C-w><Left>
"nnoremap H gT
"nnoremap L gt
nnoremap <S-PageUp> gT
nnoremap <S-PageDown> gt
"map <C-k> :MRU <CR>
nnoremap <leader>p :MRU<CR>
nnoremap <leader>r :%s/.rb./.rb/<CR>:%sort u<CR>:noh<CR>
nnoremap <leader>g :%g/.gems.*/d<CR>
imap jw <Esc>
nnoremap <silent> <C-S> :<C-u>w<CR>
inoremap <c-s> <Esc>:w<CR>
"tnoremap <Esc> <C-&gt;<C-n>
" Help FZF register escape
if has("nvim")
  au TermOpen * tnoremap <Esc> <c-&gt;<c-n>
  au FileType fzf tunmap <Esc>
  "au FileType fzf tunmap <Esc> <Esc>:q<CR>
endif
tnoremap <C-w>h <C-&gt;<C-n><C-w>h
tnoremap <C-w>j <C-&gt;<C-n><C-w>j
tnoremap <C-w>k <C-&gt;<C-n><C-w>k
tnoremap <C-w>l <C-&gt;<C-n><C-w>l
"map <C-n> <C-w><
"map <C-m> <C-w>>
"map <C-Up> <c-w>+
"map <C-Down> <c-w>-
" select all + yank
"map <C-a> ggVGy
"map <D-a> ggVGy
"set clipboard=unnamed
"this means the yank should copy into system clipboard
" use the clipboards of vim and win
set clipboard+=unnamed
set clipboard+=unnamedplus
set paste               " Paste from a windows or from vim
"set go+=a               " Visual selection automatically copied to the clipboard
" using tabs
map <C-t> :tabedit .<CR>
map <C-S-[> gT
map <C-S-]> gt
set pastetoggle=<F2>
"set paste
noremap Y y$
nnoremap ; :
nnoremap : ;
nnoremap <expr> gp    "[&quot;.getregtype(v:register)[0].&quot;]"
nmap <Leader>ha <Plug>(GitGutterStageHunk)
nmap <Leader>hu <Plug>(GitGutterUndoHunk)
" relative path  (src/foo.txt)
nnoremap <leader>tr :let @="rspec " . expand("%")<CR>
nnoremap <leader>ty :let @="yarn test " . expand("%")<CR>
nnoremap <leader>cf :let @*=expand("%")<CR>
" absolute path  (/something/src/foo.txt)
nnoremap <leader>cF :let @*=expand("%:p")<CR>
" filename       (foo.txt)
nnoremap <leader>ct :let @*=expand("%:t")<CR>
" directory name (/something/src)
nnoremap <leader>ch :let @*=expand("%:p:h")<CR><Paste>
nnoremap P p[v]
" clean yarn test results
nnoremap <leader>aa :%s/^FAIL/ FAIL/<CR>:%g!/^ FAIL./d<CR>:%g/^\s$/d<CR>:%s/^ FAIL */yarn test /<CR>:noh<CR>:sort u<CR>
set guioptions-=e "no gui tabs
set guioptions-=l
set guioptions-=r
set guioptions-=b
set guioptions-=L
"set go-=Lr
set display=lastline
"set dy+=lastline
"set nu
set cursorline
set sta
set ai
set si
set pi
set is
set guifont=monaco:h12
colorscheme sunburst
"highlight OverLength ctermbg=red ctermfg=white guibg=#592929
"highlight OverLength ctermbg=red ctermfg=white guibg=#300000
"match OverLength /%81v.+/
"augroup vimrc_autocmds
  autocmd BufEnter .js highlight OverLength ctermbg=darkgrey
  autocmd BufEnter .js match OverLength /%80v./
  autocmd WinEnter .js* highlight OverLength ctermbg=darkgrey
  autocmd WinEnter .js match OverLength /%80v.*/
autocmd BufEnter .rb highlight OverLength ctermbg=darkgrey
  autocmd BufEnter .rb match OverLength /%80v./
  autocmd WinEnter .rb highlight OverLength ctermbg=darkgrey
  autocmd WinEnter .rb match OverLength /%80v./
"autocmd BufWinEnter * highlight OverLength ctermbg=darkgrey guibg=#300000
  "autocmd BufWinEnter * match OverLength /%80v./
  "autocmd BufRead  highlight OverLength ctermbg=darkgrey guibg=#300000
  "autocmd BufRead * match OverLength /%80v./
  "autocmd BufAdd  highlight OverLength ctermbg=darkgrey guibg=#300000
  "autocmd BufAdd * match OverLength /%80v./
  "autocmd BufNewFile  highlight OverLength ctermbg=darkgrey guibg=#300000
  "autocmd BufNewFile * match OverLength /%80v.*/
"augroup END
"set colorcolumn=81
" Vim starts in normal mode
hi CursorLine guifg=NONE guibg=#0d0d0d gui=NONE cterm=none ctermbg=17
hi CursorLine guifg=NONE guibg=#0E0E0D gui=NONE cterm=none ctermbg=17
" Change Color when entering Insert Mode
autocmd InsertEnter * hi CursorLine guifg=NONE guibg=#0d0d0d gui=NONE cterm=none ctermbg=233
" Revert Color to default when leaving Insert Mode
autocmd InsertLeave * hi CursorLine guifg=NONE guibg=#0d0d0d gui=NONE cterm=none ctermbg=17
" Resize panes when window is resized
autocmd VimResized * wincmd =
"function! AddFrozenStringHeader()
  "if getline(1) !~ "frozen_string_literal"
    "call append(0, '# frozen_string_literal: true')
    ""call setline(1, '# frozen_string_literal: true')
  "endif
"endfun
"autocmd BufNewFile .rb call AddFrozenStringHeader()
"autocmd BufWritePre .rb call AddFrozenStringHeader()
" https://vi.stackexchange.com/questions/5949/substitute-with-pure-vimscript-without-s
"function! AddSpaceBeforeEqualInWholeBuffer()
"    let l = 1
"    for line in getline(1,"$")
"        call setline(l, substitute(line, '([^= ])=', '\1 =', "g"))
"        let l = l + 1
"    endfor
"endfunction
"fun! autoHEADER#update_modified_time()
"    let cursor_pos = getpos('.')
"    silent! exe "1,10s/\(Last Modified\s\+:\s\+\)\[[^\\]]\+\]/\1[" . strftime("%Y-%m-%d %H:%M") . "]/" 
"    call setpos('.',cursor_pos)
"endfun
"au BufEnter * setlocal cursorline
"au BufLeave * setlocal nocursorline
augroup CursorLine
  au!
  au VimEnter,WinEnter,BufWinEnter * setlocal cursorline
  au WinLeave * setlocal nocursorline
augroup END
"set foldmethod=syntax
"set foldnestmax=2
"set foldlevelstart=1
set statusline+=%#warningmsg#
"set statusline+=%{SyntasticStatuslineFlag()}
set statusline+=%*
set statusline+=%=
set statusline+=%l    " Current line
set statusline+=:    " Separator
set statusline+=%c    " Column
" Use Neomake instead of syntastic
"let g:syntastic_always_populate_loc_list = 1
"let g:syntastic_loc_list_height = 5
"let g:syntastic_auto_loc_list = 0
"let g:syntastic_check_on_open = 0
"let g:syntastic_check_on_wq = 1
"let g:syntastic_check_on_w = 1
"let g:syntastic_javascript_checkers = ['eslint']
"let g:syntastic_ruby_checkers = ['mri']
""let g:syntastic_ruby_rubocop_exec = 'rubocop'
""let g:syntastic_ruby_rubylint_exec = 'ruby-lint'
"let g:syntastic_quiet_messages = {}
let g:syntastic_error_symbol = '❗'
let g:syntastic_style_error_symbol = '❗'
let g:syntastic_warning_symbol = '❗'
let g:syntastic_style_warning_symbol = '❗'
"let g:syntastic_error_symbol = '!'
"let g:syntastic_style_error_symbol = '!'
"let g:syntastic_warning_symbol = '!'
"let g:syntastic_style_warning_symbol = '!'
"let g:PyLintDissabledMessages = ""
"'C0103,C0111,C0301,W0141,W0142,W0212,W0221,W0223,W0232,W0401,W0613,W0631,E1101,E1120,R0903,R0904,R0913'
"let g:javascript_conceal_this = "@"
"set conceallevel=1
highlight link SyntasticErrorSign SignColumn
highlight link SyntasticWarningSign SignColumn
highlight link SyntasticStyleErrorSign SignColumn
highlight link SyntasticStyleWarningSign SignColumn
"autocmd FileType javascript inoremap <silent> <buffer> @ <C-r>=syntax_expand#expand("@", "this")<CR>
autocmd FileType javascript inoremap <silent> <buffer> clog <C-r>=syntax_expand#expand("clog", "console.log()")<CR><Left>
autocmd FileType javascript inoremap <silent> <buffer> cnam <C-r>=syntax_expand#expand("cnam", "className=&quot;&quot;")<CR><Left>
"autocmd FileType javascript inoremap <silent> <buffer> < <C-r>=syntax_expand#expand_head("<", "return")<CR>
"autocmd BufNewFile,BufRead .slim setlocal filetype=slim
autocmd BufNewFile,BufRead,BufWinEnter .slim setlocal syntax=slim
" load local .vimrc from project directory
set exrc
" Hide one or two two-space indents
"syntax match HideTwoIndents /\v^  (  )?/ conceal
" (Optional) Hide regardless of cursor position
"set concealcursor=nvic
" Hide concealed matches without replacement chars completely
"set conceallevel=2
if exists('g:started_by_firenvim')
  au BufEnter github.com_.txt set filetype=markdown
  au BufEnter tasks.hubstaff.com_.txt set filetype=markdown
  set guifont=10
else
  "set laststatus=2
endif
autocmd FileType python setlocal tabstop=2 softtabstop=2 shiftwidth=2 expandtab
" do not jump to first search
set noincsearch
set hlsearch
" Enable seeing-is-believing mappings only for Ruby
augroup seeingIsBelievingSettings
  autocmd!
autocmd FileType ruby nmap <buffer> <Enter> <Plug>(seeing-is-believing-mark-and-run)
  autocmd FileType ruby xmap <buffer> <Enter> <Plug>(seeing-is-believing-mark-and-run)
autocmd FileType ruby nmap <buffer> <F4> <Plug>(seeing-is-believing-mark)
  autocmd FileType ruby xmap <buffer> <F4> <Plug>(seeing-is-believing-mark)
  autocmd FileType ruby imap <buffer> <F4> <Plug>(seeing-is-believing-mark)
autocmd FileType ruby nmap <buffer> <F5> <Plug>(seeing-is-believing-run)
  autocmd FileType ruby imap <buffer> <F5> <Plug>(seeing-is-believing-run)
augroup END

:CocInfo result:

## versions
vim version: NVIM v0.8.2
node version: v16.15.1
coc.nvim version: 0.0.81-bacd91d7 2022-06-03 10:34:52 +0800
coc.nvim directory: /home/michal/.vim/plugged/coc.nvim
term: tmux
platform: linux
Log of coc.nvim
2023-03-01T21:54:39.461 INFO (pid:1218280) [plugin] - coc.nvim initialized with node: v16.15.1 after 81ms
2023-03-01T21:54:44.898 INFO (pid:1218280) [services] - registered service "solargraph"
2023-03-01T21:54:45.293 INFO (pid:1218280) [extension:coc-solargraph] - Solargraph is listening PORT=45811 PID=1218391
2023-03-01T22:28:06.937 INFO (pid:1218280) [attach] - receive notification: checkJsonExtension []
2023-03-01T22:28:06.966 INFO (pid:1218280) [services] - registered service "json"
2023-03-01T22:28:06.967 INFO (pid:1218280) [services] - Json language server state change: stopped => starting
2023-03-01T22:28:07.039 INFO (pid:1218280) [services] - Json language server state change: starting => running
2023-03-01T22:28:07.042 INFO (pid:1218280) [services] - service json started
2023-03-01T22:28:12.336 INFO (pid:1218280) [attach] - receive notification: showInfo []

Answer 1

The automatic completion menu on typing is a standard feature of Coc.

But it seems that on Neovim it is not compatible with the :set paste option.

I propose you comment the following option:

set paste

As @Ben point out when paste is set the keyboard input it taken literally by Vim and Coc way to detect keyboard input (TextChangedP) is deactivated.