I worked with third party thermal printers a while back this is where I put the notes has some usb info
Devterm might store the files a little differnently in terms of location but lsusb should indicate all ports you may have to run as root:
sudo lsusb
Dev term should have like ~10 devices including a linux foundation root hub…
at root prompt on the devterm (terminal emulator)
cd … (this takes you up one root directory)
cd dev/usb
when you do dir there it will tell you the directory is hidden… so that won’t be much help and I can’t seam to get into that directory on mine either so no problem - use lsusb to troubleshoot for your 3d printer device
using the gui file system you should be able to see a folder /dev/usb/ but the contents are hidden…
at a minimum the devterm thermal printer should be there as welll as the internal uart for the usb hub…
notes on my printer search: