Thanks for the help but i got another issue.
I'd like to check if the created mgmt user already exists in the customer domain.
When i try the following for example, i'm getting just a empty response:
Get-AdmUser -Filter * -AdaxesService localhost -Server $domain
When i use the AdmGroup cmdlet i get a full list of all groups as expected.
Get-AdmGroup -Filter * -AdaxesService localhost -Server $domain
I didn't thought there is a difference in this cmdlet execution, but as it seems it does?