You manage users on the Edge Device.
In the screen "My User Groups", you enable access to apps that are installed on the Edge Device. To do this, you create groups and provide users access to the apps assigned to those groups. In this way, you grant access to your own apps to the invited members of the group. After new users are invited to a group, all members of that group can just start or stop the app, for example, depending on the authorizations assigned to the group.
You can find more information in the documentation Industrial Edge Device – Operation.