API key not valid

I’m learning firebase through Firebase Android Codelab - Build Friendly Chat I’ve done all coding according to instruction till the end of Enable Authentication section. But when trying to test the app I encounter with the following message: 2021-11-13 09:42:17.083 4741-4741/? E/AuthUI: A sign-in error occurred. com.google.firebase.FirebaseException: An internal error has occurred. [ API key not valid. Please pass a valid API key. ] at com.google.android.gms.internal.firebase-auth-api.zzto.zza(com.google.firebase:firebase-auth@@21.0.1:4) at com.google.android.gms.internal.firebase-auth-api.zzuw.zza(com.google.firebase:firebase-auth@@21.0.1:9) at com.google.android.gms.internal.firebase-auth-api.zzux.zzl(com.google.firebase:firebase-auth@@21.0.1:1) at com.google.android.gms.internal.firebase-auth-api.zzuu.zzk(com.google.firebase:firebase-auth@@21.0.1:25) at com.google.android.gms.internal.firebase-auth-api.zztl.zzh(com.google.firebase:firebase-auth@@21.0.1:1) at com.google.android.gms.internal.firebase-auth-api.zzoj.zza(com.google.firebase:firebase-auth@@21.0.1:2) at com.google.android.gms.internal.firebase-auth-api.zzvb.zza(com.google.firebase:firebase-auth@@21.0.1:23) at com.google.android.gms.internal.firebase-auth-api.zzul.zza(com.google.firebase:firebase-auth@@21.0.1:4) at com.google.android.gms.internal.firebase-auth-api.zzpt.zzq(com.google.firebase:firebase-auth@@21.0.1:4) at com.google.android.gms.internal.firebase-auth-api.zztp.zzl(com.google.firebase:firebase-auth@@21.0.1:5) at com.google.android.gms.internal.firebase-auth-api.zzql.zzd(com.google.firebase:firebase-auth@@21.0.1:3) at com.google.android.gms.internal.firebase-auth-api.zzqk.accept(Unknown Source:6) at com.google.android.gms.common.api.internal.zacj.doExecute(com.google.android.gms:play-services-base@@17.5.0:2) at com.google.android.gms.common.api.internal.zah.zaa(com.google.android.gms:play-services-base@@17.5.0:9) at com.google.android.gms.common.api.internal.GoogleApiManager$zaa.zac(com.google.android.gms:play-services-base@@17.5.0:193) at com.google.android.gms.common.api.internal.GoogleApiManager$zaa.zab(com.google.android.gms:play-services-base@@17.5.0:158) at com.google.android.gms.common.api.internal.GoogleApiManager$zaa.zaa(com.google.android.gms:play-services-base@@17.5.0:126) at com.google.android.gms.common.api.internal.GoogleApiManager.handleMessage(com.google.android.gms:play-services-base@@17.5.0:164) at android.os.Handler.dispatchMessage(Handler.java:103) at android.os.Looper.loop(Looper.java:214) at android.os.HandlerThread.run(HandlerThread.java:67) It seems the the API key given in mock-google-services.json has expired. What’s the solution for this issue?

[mdsadiqueinam]

Found the solution, the issue is occurring because if (BuildConfig.DEBUG) { FirebaseDatabase.getInstance().useEmulator("10.0.2.2", 9000) FirebaseAuth.getInstance().useEmulator("10.0.2.2", 9099); FirebaseStorage.getInstance().useEmulator("10.0.2.2", 9199) } here BuildConfig.DEBUG is giving false when app build, that why the emulator is not connection with app, make sure BuildConfig is imported from Build generated file

[nishatoma]

Was anyone able to resolve this issue?

Update: I was using the wrong BuildConfig class, I deleted some BuildConfig Import, and it ended up using the local BuildConfig class from the project, which is the correct file.