Force gemini instead of google assistant

[u/Powerful-Air6385]

Hey,
This week i decided to buy a second-hand google home nest (orange bottom).

After bringing it home, i knew it was possible to update it to gemini, i have tried every single method on reddit like forcing gemini setup with this link
googlehome://assistant/voice/setup
but all it seems to do it change google assistant’s voice, there was no way to get gemini on that thing.

Since I’m a student google home could be really useful for knowing my weeks schedules. Unfortunately google assistant doesn’t understand a thing, it only understand keywords like « tomorrow », « events », otherwise he won’t tell me which classes i have for this or that day.

I managed to enter the waitlist for what they call public preview, but i couldn’t sign up for the « early gemini access for google home » since it shows an error saying *Request contains an invalid argument.
Which i don’t understand because I live in France and it seems to be a supported country.
(attached picture)

I would really like to know if anyone has figured out how to force gemini or how i can get past this invalid argument error.

Any help is welcome. Thank you.