The Users page shows a list of all users which have access to the workspace (after they have logged in to the Apps Creator dashboard at least one time):
The primary user for the workspace is designated as the "Owner" of the workspace.
Users are not managed from within Apps Creator. Users for the current workspace are determined based upon the users that exist within the workspace's associated streaming platform property. To add users to a workspace, add them to the associated property in the Zype Admin dashboard.