Error in registering Lebara Sim card.

So I bought a Lebara Sim card today from a local super shop in Furtwangen with my friend.
After coming back home I put the sim card in my phone (Google pixel 7 pro)
When I tried registering the sim according to the instructions on the back of the pack it fails to register Everytime. But it shows Lebara in place of service and network lines are also visible.

Ps. I am an international student here and I gave my passport as identification during registration.

Anyone knows any solution for this?

Thanks in advance