On prem AD to Entra
So, your existing devices are AD joined. You should set up Entra ID Connect if you haven’t already and turn on hybrid joining. https://learn.microsoft.com/en-us/entra/identity/devices/how-to-hybrid-join This will get your devices registered into Entra. The next step is to set up the GPO to join the existing devices to Intune silently. https://learn.microsoft.com/en-us/windows/client-management/enroll-a-windows-10-device-automatically-using-group-policy You can then upload the…