How to Add Additional Consoles to the Nintendo Switch Parental Controls App
Up to three Nintendo Switch consoles can be added to the Nintendo Switch Parental Controls app.
On your smart device, launch the Nintendo Switch Parental Controls app on your iOS or Android device.
Tap the + icon in the upper-right corner.
Tap "Add a Nintendo Switch Console."
Tap "Next" to get the Registration Code for the Nintendo Switch Parental Controls app.
Use the Registration Code to link the Nintendo Switch console.