Currently, it’s rolling out in the Gemini app. When you use the “Create image” option, you’ll see a tooltip saying “Generating image with Nano Banana Pro.”

And in AI Studio, you need to connect a paid API key to use it:

https://aistudio.google.com/prompts/new_chat?model=gemini-3-...

> Nano Banana Pro is only available for paid-tier users. Link a paid API key to access higher rate limits, advanced features, and more.