After getting an USB-C cable, I was having trouble connecting the Mudita Pure on Debian (Bullseye version) and I figured out the issue.
You need to add yourself to the “dialout” group. In my case, that looked like this:
sudo usermod -a -G dialout sandra
As usual, after adding yourself to groups, you normally need to logout and log in again. (In my case, that meant restarting xrdp since I was logged in over xrdp.)