Click on the gear icon in the main menu, then hover the word Users, and click on Configure.
The user’s list shows all of the roles currently available, by default Superuser and Disabled user are there.
Click on any role to show all of the users that fall under that role.
To add a role, click on + in the top and on Role.
Assign a Name to the new role and click on the Save icon to complete the procedure.
Change or delete an existing role by right clicking it (or holding, on the tablet) and selecting the corresponding word.
It is not possible to eliminate the role of Superuser and Disabled user, nor a role that contains some users.
To assign a role to a user, drag it in towards the role that you want to assign to it.