Impossible to connect with my cellphone

I have a Samsung phone. I used the app last year. I tried to connect again today, I do have a code on the technology book of my sun (we are homeschoolers), this code was working last year, and now I am block at the connection step.
I have tried to "connect with code", I have scanned the QR code which is on the technology book (Cahier Technologie 4ème Nathan), I have ticked "Use Legacy connection", I have unticked "Use Legacy connection". Nothing is working and I'm just blocked at this step. Any suggestion?

what is the version of your ai companion?