In Pro Workspaces there are 3 types of users. In Free workspaces, there is no user management.
The three types of users in Pro Workspaces are:
Billing Owner: This is the primary account of the Workspace. The billing owner has Admin rights and can also manage the billing information for the Workspace. The Billing owner is the person that created the Workspace and then upgraded it to Pro.
Admin: Admins can add and remove workspace members, see all Workspace projects, and edit all Workspace projects. First add a person as a Workspace member then you can change their rights to Admin.
Member: A member can create projects in a Workspace and edit any Workspace project they have been invited too. You need to first add a Member to the Workspace before you can add them to projects in the Workspace. Any member can be turned into an Admin in the team management area.
To add a member to a workspace, click on the MEMBERS icon on the left-hand navigation menu.