Unsupervise an iPhone, iPad, or Apple TV in Apple Configurator 2
Unsupervising an iPhone, iPad, or Apple TV erases all content and settings on the device, including apps and media. If you want to preserve the data on a supervised device, make a backup of it first. Supervised device backups are handled in two different ways:
When restored to the original device, that device is still supervised.
When restored to any other device, that device is unsupervised but available for supervision.
You can unsupervise a device by erasing all content and settings. See Erase a device.