Why is authentication not working on own domain but working on firebase's domain?

Question

If you go to https://wfolly.firebaseapp.com/, you'll be able to log in with Facebook by clicking "Iniciar sesion". You'll then see your name next to the log out text "Cerrar sesion - YOUR FACEBOOK NAME".

However, while auth works on wfolly.firebase.com above, it does not work on https://debatenomasafp.org/, my own domain connected through Firebase Hosting to Firebase's own wfolly.fire(...) URL.

"Does not work" means you won't see your name next to the log out text "Cerrar sesión", and generally won't be able to interact with the website as if you were logged in.

What is wrong? Why are they not behaving identically?

I know the deployment version is the same in both sites because the current deployment reflects a late change in both URLs, not just Firebase's.

Authentication also works fine on localhost:8080 pre-deployment.

It may or may not be relevant that I am using Re-Base (github.com/tylermcginnis/re-base) for authentication requests.

Answer 1

Kato, in the comments above, gave me the answer through Slack.

I simply had to authorize the new domain in Firebase's console's "OAuth redirect domains" setting, under "Authentication".

Answer 2

Just adding to the answer above. Thought an image would be helpful ;)