limit numbers of active / started MaxSurf app.

We have 3 desktops for 3 users and one (1) license for 

MAXSurf QLT

MAXSurf Advanced QTL

MAXSurf Ent QTL

How Can I limit number of active session to 1 ? So only one user at time can use program with  no possibility to run extra instance (becasue of cost for li.)

We are using cloud based portal (no local server) . Are there any checkbox to limit session just to number of license ?