it is unclear how I should sign with a Trezor. It is connected to my laptop, but signing only seems to work with QR codes.
Any suggestions how I can sign with my Trezor ?
Normally you just have to press the "Sign" button and it will give you a prompt to "scan" for hardware wallets.
Then you will need to plug in your Trezor using the USB and it will find it.
Then you will need to press the "Sign" prompt that will appear.
It will ask you for your Trezor's PIN and after putting it, you 'll be able to sign.