If you want to connect your domain to Microsoft 365, we recommend the following method:
In order to use Microsoft 365 with your own domain, you must first validate that you own the domain so that no one else tries to use your domain for your Microsoft services without your permission.
To do this, a so-called TXT entry for your domain must first be set via the easyname controlpanel.
You will receive this TXT entry in the Microsoft 365 admin console