Gemini API returns 403: Your project has been denied access

Hello,

My project ID is mandrill-508107.
Project number: 1067223411592.

A simple “Hello” request to gemini-3.6-flash returns:
403: Your project has been denied access. Please contact support.

The error also occurs when calling the API directly outside my application. Creating a replacement API key did not resolve it.

Could you review the project’s access restriction and confirm whether it is eligible for free-tier usage?

Thank you.