An "End User" or "Sub" account is an account that can be given to access only specific servers. Access is limited to using the API or issuing restores via the GUI. Access is only granted to selected servers. 

To create a sub account navigate to the "Users" tab in the Bacula4 system. 

2) You will be presented with a screen listing all sub accounts. Click "ADD USER"

3) You can fill in the user's information on this screen. Include which servers they have access to.

 

4) Click the "ADD USER" button again to save. 

This user can now login to the web GUI and manage the server(s) allocated to them.