Error: Google id_token is not allowed to be used with this application. Firebase access fails after it was working

Question

I'm using Google SignIn and then authenticate on Firebase using signInWithCredential, passing the Google credentials.

I followed all the procedures, and everything was working! And suddenly it stops working. I went to a previous working code and it still fails. So it seems something happened with the database configuration.

In Firebase DB I already checked:

• DB is up and running. As a fact I can read when not logged (as I have defined by rules)
• Sign-in method for Google is still ENABLED
• My App is still registered the project configuration, including their SHA1 signature (for debug and release version)
• I have confirmed the google-services.json file downloaded from configuration still match my app json file

After Google login finish Ok, the error message is as follows as I get from my try-catch with task.getException in the listener:

com.google.firebase.FirebaseException: An internal error has occurred. [ Invalid Idp Response: the Google id_token is not allowed to be used with this application. Its audience (OAuth 2.0 client ID) is XXXXX-XXXXX.apps.googleusercontent.com, which is not authorized to be used in the project with project_number: XXXXX. ]
     at com.google.android.gms.internal.zzago.zzew(Unknown Source)
     at com.google.android.gms.internal.zzagl$zzg.zza(Unknown Source)
     at com.google.android.gms.internal.zzagw.zzex(Unknown Source)
     at com.google.android.gms.internal.zzagw$zza.onFailure(Unknown Source)
     at com.google.android.gms.internal.zzagr$zza.onTransact(Unknown Source)
     at android.os.Binder.execTransact(Binder.java:453)

(I changed my project info to XXXX)

What else could have changed in the Firebase configuration? Please help!

Edit: SOLVED, as described below. You need to also take a look at the Google API console at https://console.developers.google.com/apis/credentials

Answer 1

1. You have to create Web-client Oauth 2.0 id here https://console.developers.google.com . After that you will have client id and secret
2. Open https://console.firebase.google.com and goto Authentication -> Sign-in method -> Google -> Web SDK configuration and use client id and secret you have got on the step 1. in Web client ID & Web client secret.