Flycheck eslint with Emacs

Question

I'm very new to Emacs and have been searching all day to add eslint to Flycheck.

When I run C-c !-v in a React project:

  javascript-eslint
    - major mode:  `help-mode' not supported
    - may enable:  Automatically disabled!
    - executable:  Found at /usr/local/bin/eslint
    - config file: missing

I want to use the config file for the root project. How can I do this?