the vCenter GUI offers the ability to add an identity provider like Microsoft AD. In some cases this won’t work. For example if you are not a domain admin and you have to specify in which organisation unit the computer object should created. The computerobject should not exists. Delete an already exiting object, it would be created during the join process!
Continue reading VMware vSphere: Join a vCenter VCSA Appliance to an Active directory domain by command line