How to turn off restrictions if password forgotten without erasing phone

If you mean your Screen Time password see this guide→If you forgot your Screen Time passcode - Apple Support or watch this companion video:

Note that for this to work you had to enter an Apple ID and password when first setting the screen time passcode. If you didn’t, or don’t know what they were, the only option is to restore the phone to factory settings, then set it up as a new phone without restoring a backup.