No air printer found

We have to assume that you have an AirPrint-capable printer nearby that you have successfully been printing to from this iPhone previously ... correct?

What have you tried, so far yourself, to resolve this so that we don't try offering you potential solutions that may not have already worked for you?

Hi,

Assuming that all settings are OK and that your printer is an AirPrint model, you may want to try a full power-cycle sequence (do not forget the router): Power off the router, the printer, the iPad, the iPhones, the Macs, 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, the iPhones and the Macs. Finally, power on all other devices/computers.

From this article:

Use AirPrint to print from your iPhone or iPad - Apple Support

“AirPrint devices connected to the USB port of an Apple AirPort Base Station or AirPort Time Capsule, or to your computer using Bluetooth connection, can’t use AirPrint.”

Well, you have told us nothing at all about the specifics of your situation!

”No AirPrint printer found” would be perfectly normal if there were no printer on your network, or the specific printer was not AirPrint capable.

About AirPrint - Apple Support

Thank you for the report. Glad to hear that. You're welcome!