Rademacher USB Duofern Stick

Good morning, excuse my bad English. I am from Gerrmany.

I have installed Home Assistant on a Raspi 4. Everything worked well. But not Duofern from Rademacher.
I followed the instructions from Github. (pyduofern-hacs)

Added reposity. Installed in Hacs and rebooted. The USB duo remote stick was also found.
Unfortunately no roller shutters. Github says that I can add devices using the “duofern.start_pairing” command.
Where do I have to enter this command? The error message appears in the terminal: zsh: command not found: duofern.start_pairing.

Greetings
Mecky B.