reset iphone without losing data

Why do you think you might need to reset your device?

A reset WILL completely erase the device - returning it to a “just out of the box” state - and allow a recovery of data from backup.

The degree of data loss will be determined by how well (and how recently) the device was backed-up and sync’d.

How to remove your iPhone, iPad, or iPod touch passcode without a computer - Apple Support

Note: If the device is running an iOS prior to 15.2, reset instructions are linked near bottom of article in the section titled, “If you can't reset your device.”