How to use the operator ability after the war within quest?

[Raptora1]

I just completed "the war within quest" and i got really confused when I used my operator mode after completing the quest in a normal mission. Instead of using 10k dps beam that I got from my shool, which my operator used before, I walked around with the basic abilities I had in the war within quest. I thought, that there is probably a keybinding for my special ability, so I checked key bindings. I came across the markings "next power", "previous power" and "use power". I though that that was it, but when i bound the "use power" to a key, went in my operator mode and clicked it, I returned to the warframe mode instead of starting the beam. How do i use the power?

[HisHolinessAardvarkPrime]

Tapping the button for your operator (5 in my case) will give you the operator as they were in TWW. Holding down that button will give you your focus school power (once the meter is full of course)