ID cards don’t connect to the internet.

These days an ID system that doesn’t work online is next to useless.

It's an NFC card that can be read with any NFC card reader, USB or smartphone based.

https://www.ausweisapp.bund.de/en/open-source I just saw that it's available in alpine.

So I tried installing it on my postmarketOS smartphone and it runs out of the box: https://i.imgur.com/nRIAyrq.png

My Shift6mq is listed has not having NFC support in postmarketOS, so I can't actually test it, but I assume the USB card reader option will work once it's supported.