HI
Since server 2019 essentials has removed server essentials experience role, it is by design.
So the steps for migration DC is similar as the steps for migration from server 2012 standard/wse to server 2019 std.
we can refer below AD and DHCP migration video to do migration steps.
Migrating Active Directory From Windows 2012 R2 to Windows Server 2019
https://www.youtube.com/watch?v=tPBzipZNXRo
Migrate From Server 2012 to Server 2019 Domain Controllers
https://www.petenetlive.com/kb/article/0001731
DHCP migration from Windows Server 2008R2/2012R2 to Windows Server 2016 (Step by step guide)
https://www.youtube.com/watch?v=8wdaeY7YmbY
Please Note: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice.
Trying to migrate a domain from Server 2012 R2 Essentials to a new Server 2019 Standard server
https://social.technet.microsoft.com/Forums/windowsserver/en-US/693e3ce9-f41b-4b4d-ae52-112142a92d84/trying-to-migrate-a-domain-from-server-2012-r2-essentials-to-a-new-server-2019-standard-server?forum=winserveressentials
There are other steps (including but not limited to these steps) listed here:
(1)Full system backup for wse2012 (System state & Data)
(2)Installing wse2019 on new server and add it to existed wse2012 domain.
(3)Migrating Folders, folders and shares from wse2012 to wse2019
(4)Migrating DHCP to hardware router or wse2019 and check if migration successfully.
(5)Raising Forest and Domain Functional Level Windows Server 2008, then migrate FRS to DFSR ,before promote wse2019 as replica DC.
(6)Promoting wse 2019 to PDC (Primary Domain Controller)
(7)checking replication between both DC servers.
(8)Transfering all FSMO from wse2012 to wse2019
(9)Removing AD service from wse2012
(10)Unjoining all Computers Workstations from wse2012 and join them to wse2019
(11)Removing wse2012 server from the network.