Unable to AirPrint from iPad

See:

• Use AirPrint to print from your iPhone, iPad, or iPod touch - Apple Support
• Connect an AirPrint printer to a Wi-Fi network - Apple Support

Apple AirPrint is a driverless connection protocol. A high proportion of modern printers intended for Home, SoHo and Business environments now support AirPrint. Check your printer model against this list:

About AirPrint - Apple Support

Do you have any security Apps (such as Norton) or VPN installed on your iPad? If so, these may be interfering with your iPad's internal routing table - and may interfere with AirPrint/AirPlay/WiFi Hotspot or other Apple services. If present, it may be necessary to temporarily remove such Apps from your iPad - and then perform a forced-restart.

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.

• On an iPad with Face ID: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

If you continue to have difficulties, check to see if your iPad is using the new WiFi Private Address feature. This feature is intended to provide additional privacy and security when using “public” (untrusted) WiFi networks.

Settings > WiFi > [Your WiFi Network / SSID] - tap the “i” icon - Private Address

The Private Address feature is largely unnecessary for your home WiFi network; if enabled, Private Addressing can interfere with anticipated operation of other devices, such as AirPrint/Airplay. In such circumstances, you may need to disable this feature - and can be enabled or disabled for each individual network.

Use private Wi-Fi addresses in iOS 14, iPadOS 14, and watchOS 7 - Apple Support

You’ve got this somewhat working, but also check the printer for available firmware updates, for whichever vendor and model printer this is. Same for your Wi-Fi router.