How to unlock without password

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

How to reset your passcode without a computer if you have iOS 15.2 or higher.

How to reset your iPhone, iPad, or iPod touch when you forgot your passcode - Apple Support

How to reset your passcode using a computer.

If you forgot your iPhone passcode - Apple Support

Assuming that you mean the passcode you need to enter to start and unlock the phone …

… there is no way; the phone must be reset (erased) and restored from an available backup.