1) Be sure you are a member of the lp group . İf not :

sudo gpasswd -a YOUR_USER lp

then relogin or reboot

2) Then install capt-src from aur

i used yay for it. An be sure cups installed as a dependency of capt-src

yay -S capt-src
sudo pacman -S cups

3) Enable and check cups

systemctl start org.cups.cupsd.service
systemctl status org.cups.cupsd.service 
# At this point you must see "active" status without errors as an output. 
# If you see some errors that means that you are missing something
# After everything goes well enable the service permenantly
systemctl enable org.cups.cupsd.service

4) Check where is your printer rested. In py pc it is on lp1

ls /dev/usb/lp*

5) Enable and check capt

sudo /usr/sbin/lpadmin -p LBP2900 -m CNCUPSLBP2900CAPTK.ppd -v ccp://localhost:59687 -E
sudo /usr/sbin/ccpdadmin -p LBP2900 -o /dev/usb/lp1 # lp1 is our printers port that we checked before
sudo systemctl start ccpd.service
sudo systemctl status ccpd.service # Status must be active without any errors
sudo systemctl enable ccpd.service

6) If everything goes well you must see "Redy to print!" mesage after below lines

captstatusui -P LBP2900 


Note: Restarting or relogin is important after you add yourself to the lp group