Set a default MDM server for device type in Apple Business Manager
You can set an MDM server as the default server for any specific device types not already enrolled in Apple Business Manager. For example, this allows you to assign an entire order of 5000 iPad devices to a single MDM server automatically.
Set a default MDM server
In Apple Business Manager , tap Settings at the bottom of the sidebar, then select Device Management Settings .
Tap Edit in the Default Device Assignment row.
Select the default MDM server for each device type, then tap Apply.