If you want to migrate a client's domains from one DirectAdmin server to another. You can utilize the Migration function within the module.
Go to the Service Page of the Hosting package for the client
In the middle of the rows, you should see a Migrate option along with other available provisioning server for this module.
On the next page, you will be able to set which domains to skip, update the plan's server, and remove the domains from the source server after migration
Once you are ready, Add to Migration Queue and the migration will start on the next cronrun.