It isn't an useable ability.... It is like focus, it is something that you have to build up. You get Singularity by using Force Exhaustion and Force Stasis. Again look at this page. http://www.noxxic.com/swtor/pve/jedi...-and-cooldowns
. It shows you the icon for Singulanity and it will show up where your buffs show up above you focus bar.