My Gemini API requests return:
HTTP 403 PERMISSION_DENIED
“Your project has been denied access. Please contact support.”
Project ID: gen-lang-client-0753877..
Model: gemini-3.8-flash
The Generative Language API is enabled.
Google AI Studio shows Billing Tier: Unavailable.
A direct API test outside my app returns the same error.
How can I identify and resolve this project access restriction?