The Canon TR4722 is listed as a supported AirPrint model in About AirPrint - Apple Support.
Check that the printer and the iPad (or iPhone) are connected to the same network (Wi-Fi router).
Use AirPrint to print from your iPhone or iPad - Apple Support
If necessary, WPS can be used for a simplified printer connection to the Wi-Fi router (if your router supports it).
https://support.usa.canon.com/kb/s/article/ART180475
After checking all settings/connections, you may want to try a full power-cycle sequence (do not forget the Wi-Fi router):
- Power off the Wi-Fi router, the printer, the iPad/iPhone, and all other devices/computers.
- Wait two to three minutes.
- Power on the router.
- Wait two to three minutes.
- Power on the printer.
- Wait a minute or two.
- Power on the iPad/iPhone, and all other devices/computers.