where to get HP ios apps for a printer 6455e

There are no iOS apps for any brand of printer. Printing from an iOS device (iPhone, iPad, etc) is done wirelessly to any printer that is AirPrint compatible. The HP 6455e is AirPrint compatible. Check your owners guide on how to turn it on.

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

Hi,

As lkrupp indicated, the HP ENVY 6455e All-In-One Printer is a printer with AirPrint support.

About AirPrint - Apple Support

In order to use AirPrint, the printer and the iPhone (and/or iPad, and/or Mac) must be connected to the same network (Wi-Fi router).

However, a printer manufacturer may require the use of a special app (and an always active Internet connection) for certain setup and ink management purposes and extra services. Generally speaking, it is always wise to check all requirements/conditions before accepting a "free" ink offer.

https://apps.apple.com/us/app/hp-smart/id469284907 (iOS/iPadOS)

https://apps.apple.com/us/app/hp-smart-for-desktop/id1474276998?mt=12 (macOS)