Signing your iOS app with ad-hoc profiles makes it easy to deploy your latest build. But registering devices in the Apple Developer portal and keeping the profile up to date is cumbersome. Through App Center, provision tester devices in a distribution group, enabling a seamless release all testers can install when updates are available. This video demonstrates how to register devices, and re-sign apps for deployment to a distribution group?.
Read more about this at https://docs.microsoft.com/en-us/appcenter/distribution/auto-provisioning. Read how to make registration automatic: https://docs.microsoft.com/en-us/appcenter/distribution/groups#automatically-manage-devices.