Disconnect federation from a domain in Apple Business Manager
If you no longer plan to use federated authentication with a domain, you can disconnect the domain. This process doesn’t affect the domain verification.
Note: You can’t disconnect from a federated domain if Apple Business Manager is in the process of enabling federation or the account transfer process hasn’t been completed.
Disconnect federation from a domain
In Apple Business Manager
, sign in with a user that has the role of Administrator or People Manager.Select your name at the bottom of the sidebar, select Preferences
, then select Managed Apple Accounts 
.Select Manage next to the domain you want to remove federation from, then turn off “Sign in with [name of identity provider].”
Select Confirm.