support system assigning topics to users

Hi,

I installed support system on my multisite and activated it. Created users to bbe assigned for support purpose. But while creating ticket categories I am not able to assign the users,I can set only me(super admin) to all categories. Please advice me on how to assign tickets to my support staffs.

Also, From where do the assigned users answer to the tickets? If from network dashboard How to hide all other menus?