it’s possible for you to use that PIN on your switch to temporarily disable parental controls.
Parental controls will remain off until the console enters Sleep Mode.
Tap theDisable Alarms for Todaytoggle.
Wait for the change to occur.
Your phone and the Switch both need to be connected to the internet for the change to occur.
How Do You Remove Nintendo Switch Parental Controls?
Otherwise, you gotta contact Nintendo for a Master Key, if you’ve forgotten the PIN.