If you you are using admob you need to add the APK key like this: Code: <application android:label="@string/app_name" android:icon="@drawable/icon" android:allowBackup="true" android:name="androidx.multidex.MultiDexApplication"> ... <meta-data android:name="com.google.android.gms.ads.APPLICATION_ID" android:value="ca-app-pub-yourkey"/> ...