Ich hatte den Post aus versehen erst auf englisch geschrieben weil ich so an die Sprache gewöhnt bin - hier also noch mal dasselbe in grün bzw auf Englisch, vielleich ja für nicht deutsch Lesende interessant.
what megavolt said is probably it:
/dev/usb/lp1 → /dev/usb/lp0
I have a Canon LBP2900B - not exactly the same but likely very similar.
I used the Arch Wiki re Canon CAPT that was already mentioned
which is a bit scattered, itself only describing the setup of the ccpd (CAPT) part.
Before that, Cups has to be set up - there is a link on how to do that per command line in the Wiki .
There is also a link to an Ubuntu help page, describing the procedure for different Ubuntu releases and printer models.
This is how I installed it:
(recounted from going through my bash history)
systemctl status cups
(enable and start if not already running)
sudo lpadmin -p LBP2900B -m CNCUPSLBP2900CAPTK.ppd -v ccp://localhost:59687 -E
(add the printer to cups - it didn’t work with ccp://localhost:59787 but they do mention this in the wiki)
sudo ccpdadmin -p LBP2900B -o /dev/usb/lp0
(I used /dev/usb/lp0 because that is the device file that gets created when I plug in the printer)
Check with:
ls /dev/usb/
then start and enable the ccpd service:
systemctl start ccpd.service
systemctl enable ccpd.service
Don’t forget to enable (not just start) both services.
I then rebooted - and it worked. 
I then chose to use socket activation
(for no reason other than I don’t print very often and thought that it would save resources by only starting cups when actually needed):
systemctl disable cups.service
systemctl stop cups.service
systemctl enable cups.socket
systemctl start cups.socket
and it still works