fromResource
The options from GoogleService-Info.plist, or null when the bundle has none; the context is ignored.
The default FirebaseOptions of the platform's configuration, mirroring FirebaseOptions.fromResource(Context) from the Firebase Android SDK as a top-level function with the Context widened to Any? so that common code can call it. On Android they come from the resources generated by the Google Services Gradle plugin from google-services.json, on Apple platforms from GoogleService-Info.plist (the context is ignored); JS has no default configuration and returns null, as Android does when the resources are missing.
Always null: JS has no default configuration to read options from.