How to Setup on Factory Reset Phone:
Crucial Steps
Turn on the phone or factory reset to the first "Welcome / Hi there / Select Language" screen.
Tap 6 times anywhere on the blank empty area of the Welcome screen to launch the built-in QR scanner.
Connect to Wi-Fi if prompted. (Tip: If phone has a SIM card with no data balance, remove SIM card during Wi-Fi setup).
Scan the QR code shown above. The system will download the management app and grant permanent Device Owner privileges.
Why does "Ask IT Admin" happen? If you proceed past language selection or add any account / SIM PIN before scanning, Android blocks Device Owner. You MUST scan at the very first Welcome screen.
How to Enroll iPhone / iPad into Enterprise Supervision: