[Rails] Re: devise_token_auth in --api application - sign_in action doesn't work after second deploy on heroku

IndexError (string not matched) is not a database error. Your data is probably fine, but you can run `heroku run console` and check your user records. IndexError often comes up when your code treats a string as a hash, but there isn't enough information here to see what's going on. Is there a

[Rails] devise_token_auth in --api application - sign_in action doesn't work after second deploy on heroku

Hello, I've the question about the "devise_token_auth" gem, authentication in Ruby on Rails application (API) and deploying it to Heroku. *Introduction* What I did: 1/ Created an --api --database=postgresql app 2/ Added some required gems like gem 'devise_token_auth' gem 'omniauth' gem 'rack-c