no pg_hba.conf entry for host error in golang postgres connection( using heroku db)

Question

What I wrote psqlInfo := fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s sslmode=disable", host, port, user, password, dbname)
error thrown - no pg_hba.conf entry for host "", user "xyz", database "xyz", no encryption

when i set sslmode = allow then also it throws error "unsupported sslmode "allow"; only "require" (default), "verify-full", "verify-ca", and "disable" supported"