Show unmanaged accounts using your domain in Apple Business Manager
After a domain has been verified by Apple, Apple Business Manager performs a daily scan for existing personal Apple Accounts using the domain. If any are found, the unmanaged account totals are shown in the details view of each domain.
Show unmanaged accounts using your domain
In Apple Business Manager , sign in with a user that has the role of Administrator or People Manager.
Select Preferences to go to the Accounts section under Preferences, then select Edit next to Domains.