To configure your avahi service with your printer you can use this python script: https://github.com/tjfontaine/airprint-generate with this simple command
that will automatically look in your linux cups configuration, extract your printers and generate the files for avahi.
After running the script, you will find a .service file for every printer. Now, just copy the files of the desired printers to the avahi services folder:
mv AirPrint-hpcp2025.service /etc/avahi/services
If all works well you should have this on your iOS device.