How to connect iPhone to printer?

Use AirPrint to print from an iOS device such as an iPhone, iPad, or iPod touch, or from a Mac. With AirPrint, print photos, e-mails, web pages, documents, ...

MG7720 : Printing Easily from iOS Device or Mac Using AirPrint

Hi,

Also, the following guide from Canon UK (for similar models, such as the MG7750) could perhaps be of interest:

https://www.canon.co.uk/support/consumer_products/apple_airprint_guide/

Make sure that the printer and the iPhone are connected to the same network (Wi-Fi router). AirPrint works with wireless (Wi-Fi) or wired (Ethernet) network connections. Since the Canon MG7720 is equipped with Ethernet (in addition to Wi-Fi), this model could be wired to one of the LAN ports of the Wi-Fi router instead of using a wireless printer connection, if you so wish. Ethernet may be more stable. The iPhone would connect wirelessly to the router.

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

In case of difficulties recognising an AirPrint printer, you could try a power cycle sequence in the order described (do not forget the router):

Power off the Wi-Fi router, the printer, the iPhone, and all Macs/iPads/other computers and devices. 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 iPhone. Finally, power on any Macs/iPads/other computers and devices.

This user did find a solution to do it --> Solution When IOS Devices Cannot See HP P… - Apple Community