Be it a simple installation or component installation, you will only be able to connect to vCenter Server using the SSO administrator (administrator@vsphere.local) after the installation. This is because, by default, the SSO administrator is assigned the vCenter administrator role. Most environments require other users to be able to connect to the vCenter Server. To make this possible, you will need to manually assign an access role to the user/group you would like to provide access to.
Assigning users and groups to vCenter Server
Getting ready
Make sure that the domain from which you will be selecting a group/user is added as an identity source. For instructions, read the Configuring SSO identity sources section of this chapter...