The Key Property for au2mator Self Service Portal licensing is the correct Domain Search Root or the Distinguished Name of your Active directory Environment.
There are multiple ways to get this property.
Query it with PowerShell
The easiest way is to get it with PowerShell, run this Command
“Get-ADDomain | select DistinguishedName”
Get it by Active directory Console.
Make sure the Advanced Features are select
Afterwards do a right click in your domain name and select Properties
Take a look at the distinguishedName Property at the Attribute Tab