Permission denied when generating video with Veo 3.1 Fast on paid Tier 1 project

Hello Google AI Studio team,

I am using Google AI Studio with a paid Gemini API project (Proyecto Online Business) and active prepaid billing confirmed on Tier 1. I linked a paid API key and selected Veo 3.1 Fast in the Video Playground.

Every video generation attempt returns:

“Failed to generate video: permission denied. Please try again.”

This happens consistently, even after adding funds to billing and confirming Tier 1 status in the Rate Limit dashboard. The API key shows as paid and linked correctly.

This is a legitimate low-volume creative/marketing use case (short social media video clips for a small business).

Could someone review whether video-model access is enabled for this project? Thank you!