I would like to report a critical documentation gap regarding the integration of App Check with Vertex AI in Firebase, especially for Flutter developers.

Currently, there is no mention in the official Firebase documentation that Flutter developers must initialize Vertex AI using:

final model = FirebaseVertexAI.instanceFor(appCheck: FirebaseAppCheck.instance)
.generativeModel(model: 'MODEL');

Without this step, even when App Check is properly set up across the project, the Firebase dashboard continues to show 0% verified requests under "Vertex AI in Firebase."

This not only leads to confusion but also prevents teams from safely enforcing App Check across all services, as doing so risks breaking features dependent on Vertex AI.

I strongly recommend that this initialization requirement be explicitly included in both the Firebase Vertex AI and App Check documentation sections for Flutter.