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.
Note: You can also change the default MDM server for specific device types. However, devices that are already enrolled must be manually reassigned. To change the default MDM server, follow the steps below.
Set a default MDM server for device assignment
In Apple Business Manager , sign in with an account that has the role of Administrator or Device Enrollment Manager.
Tap Settings at the bottom of the sidebar, then do one of the following:
Tap Device Management Settings below Organization Settings.
Tap an existing MDM server under MDM Servers, then tap Change under Default Device Assignment.
Select the default MDM server for each device type, then tap Done.