Cracked screen leads to unavailable iPhone

First, make an appointment at your nearest Apple Store’s Genius Bar or an Apple Authorized Service Provider for a screen replacement.

Genius Bar Reservation and Apple Support Options - Apple

Then, please follow one of these two articles based on your case to reset your passcode:

iPhone is running iOS 15.2 or later: If you see a iPhone, iPad, or Apple Vision Pro unavailable message or Security Lockout screen - Apple Support

iPhone is running an earlier iOS: If you forgot your iPhone passcode or your iPhone is disabled - Apple Support

First, you need to get your screen fixed so you can input the correct characters. Then -

If you forgot the passcode on your iPhone, or your iPhone is disabled or unavailable -

Click on the link for instructions on how to reset your passcode without a computer if you have iOS 15.2 or higher.

If you see a iPhone, iPad, or Apple Vision Pro unavailable message or Security Lockout screen - Apple Support

Click on the link for instructions on how to reset your passcode using a computer.

If you forgot your iPhone passcode or your iPhone is disabled - Apple Support

You don’t.

You will need to get it repaired, then restore it from your last backup.

Anything that was not already backed up or synced to the cloud is gone.