need to factory reset my phone it says unavailabe

First, if you regularly carry your phone in your pocket turn off Raise to Wake, and make sure the screen is facing away from your body so you don’t “butt enter” your passcode incorrectly. It may be counterintuitive, but it’s more important to protect the back of the phone, because if it breaks the phone must be replaced. If the screen breaks the screen can be easily replaced, and cheaply if you bought AppleCare+ when you got the phone. But even without AppleCare+ a screen is cheaper than a phone. Of course, the better answer is don’t carry the phone in your pocket unless it is in a full case to protect it.

To make the phone usable again, follow these instructions:

If your device has iOS 15.2 or later installed, check out this link→How to reset your iPhone, iPad, or iPod touch when you forgot your passcode - Apple Support. Otherwise:

See this Apple support link→If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support

Or watch this companion video ⬇️

After restoring the phone using one of the methods above you can restore your most recent backup.