hmm did you try clickin where it says 'gemini advanced'? I find it opens a drop down
I also found this [1]: “ Important:
A chat can only use one model. If you switch between models in an existing chat, it automatically starts a new chat. If you’re using Gemini Apps with a work or school Google Account, you can’t switch between models. Learn more about using Gemini Apps with a work or school account.”
I have no idea why the workspace accounts are such restricted.
[1] https://support.google.com/gemini/answer/14517446?hl=en&co=G...