How to add members to local group

Hello,

I am using vRA 7.1, and have configured the local vRO Authentication Provider with the following:

Authentication Mode:      vRealize Automation

Host Address:               https:....

Admin Group:               vsphere.local\vroadmingrp

Default Tenant:               vsphere.local

All works ok, but, I want to add members to the vroadmingrp in vRA Identity Manager.

If I sign on as Default Tenant Admin, I get to the 'Edit Group' screen in the 'Administration' tab, but there is no way of actually adding members to the group.

(ie. no Green Plus sign, just a screen with

  This group has the following members.

Name (0)           Email

No data selected

)

So, my question is , how do I add someone?

Regards

Tony