How to make netlify ignore gitignore and see all files

I ignored the firebase.js file containing the Firebase data URL with gitignore.

However, as shown in the picture below, netlify showed a message saying that firebase.js could not be found.
To solve this problem, I want to give netlify permission to ignore gitignore and see all files. Could you answer me how?

npm run build
Failed to compile
Module not found: Error: Can't resolve './firebase.js' in '/opt/build/repo/src'

A typical React .gitignore would not ignore firebase.js, especially considering that file, as shown here, is where you initialize Firebase in our application and create a database reference.

You can check that with:

cd /path/to/local/repository
git check-ignore -v -- src/firebase.js

But even if it is ignored, that should not prevent the npm build to run.