Hello,

the FRITZ!Box can be operated with a wide variety of suppliers and plans.
It is important that one of the following mobile networks is supported:

https://avm.de/service...

If you have any further questions or require assistance from our technical support team, please contact us by e-mail at fritzhilft(at)avm(dot)de. Please include the ticket ID #6686475 in your enquiry so that we can allocate your support ticket more quickly.

Kind regards from Berlin
Your AVM team

Unfortunately, the reception was not really optimal (although it was sold that way), so I have since switched back to the wired (DSL) version (Teleboy).