Regex not match contains string in bash

Question

I confuse with condition regex in bash with match if not contain string. I use regex: ^((?!success).)*$

and test online ok

but use it in bash not ok. It not exactly

string="success"
pattern='^((?!success).)*$'

if  [[ $string =~ $pattern ]]; then
    echo "found"
else
    echo "not found"
fi

please help me. enter image description here