iphone 5s

The restriction code is the code used to control access to things protected via Settings > General > Restrictions.

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.

The only option is to erase the device as specified in the previous link. The restrictions passcode is not needed if you use the "recovery mode" method exactly as instructed in If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support