Flutter Google Login not Getting Registered in Firebase - firebase

Question

1. The Problem
I'm trying to implement simple Facebook and Google Sign-in buttons with Firebase and Flutter, however the Google version is acting very weird. When I print the FirebaseAuth.instance.currentUser() I either get errors or prior Facebook login data.
When I login with Facebook, my account does appear on Firebase, however, the Google login seems to do nothing.
Is this something I messed up in the code below or some incompatibility problem with AndroidX with parts of these libraries? Something else?
Also, it is not very clear to me if I have to put the Project public-facing name somewhere inside my project to make the integration with Firebase work (I had to do something similar to setup the Facebook Login button).
2. The Facebook Login
I had to replace logInWithReadPermissions with signInWithCredential because recent versions have changed their API. I've also tried to use previous versions of the packages, but encountered many errors (probably due to AndroidX):
final _auth = FirebaseAuth.instance;
Future<FirebaseUser> _loginWithFacebook () async {
final facebookLogin = FacebookLogin();
final result = await facebookLogin.logInWithReadPermissions(['email']);
if (result.status == FacebookLoginStatus.loggedIn){
final FacebookAccessToken accessToken = result.accessToken;
AuthCredential credential = FacebookAuthProvider.getCredential(
accessToken: accessToken.token,
);
AuthResult signInResult = await _auth.signInWithCredential(credential);
FirebaseUser fbUser = signInResult.user;
return fbUser;
}
else{
return null;
}
}
3. The Google Login
Again, signInWithCredential seems to be the more recent API:
Future<FirebaseUser> _loginWithGoogle () async{
final GoogleSignIn _googleSignIn = GoogleSignIn();
GoogleSignInAccount googleUser = await _googleSignIn.signIn();
final GoogleSignInAuthentication googleAuth = await googleUser.authentication;
final AuthCredential credential = GoogleAuthProvider.getCredential(
accessToken: googleAuth.accessToken,
idToken: googleAuth.idToken,
);
AuthResult signInResult = await _auth.signInWithCredential(credential);
final FirebaseUser user = signInResult.user;
print(user);
return user;
}
Edit
I've tried it on an Android 9.0 (Pie) emulator and it still doesn't work.

Answer 1

Apparently, my authentication code was correct for both Google and Facebook, considering the most up-to-date API.
However I needed to integrate a SHA1 Fingerprint to my Firebase environment, which is something I didn't realize I needed to do because none of the tutorials I followed mentioned it and it can be easily dismissed when enabling the Google Sign-in method inside Firebase.
Anyway, here are the steps you will need to complete to get the SHA1 Fingerprint:
Open Command Prompt and cd C:\Program Files\Android\Android Studio\jre\bin.
Get the SHA1 key:
keytool -list -v -alias androiddebugkey -keystore %USERPROFILE%\.android\debug.keystore
Go to Firebase Console > Project settings > Add Key and add the key.