restriction passcode

See the following from Use parental controls on your iPhone, iPad, and iPod touch - Apple Support

If you forget your Restrictions passcode, you need to erase your device, then set it up as a new device to remove the Restrictions passcode. Restoring your device using a backup won't remove the Restrictions passcode.

Click on the link in the excerpt above for more details.

horiefromanaheim wrote:

I forget my restriction passcode.what I must do?

If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

You will have to erase your device and set it up as new, as described here.

Use parental controls on your iPhone, iPad, and iPod touch - Apple Support