How do you reset your restriction code

Assuming you are on iOS 11 and below since you are using the term “restrictions” (I’m using mobile so I can’t see iOS version if you put it there)

there’s no way. You will have to do an iTunes restore and set it up as new. Unless you have a backup that was made before the restriction code was set

Actually, it can now be reset using your Apple ID: If you forgot your Screen Time passcode