jak:
https://docs.microsoft.com/en-us/windows-server-essentials/install/install-and-configure-windows-server-essentials-or-windows-server-essentials-experience#BKMK_ExistingAD

Join your server running Windows Server Essentials to an existing domain as follows:

If you want this server to be a domain controller, set up the server as a replica domain controller.

If you do not want this server to be a domain controller, join this server to your domain by using the Windows native tools.