What does AP stand for?

I think this is Action Points.

The points you need to spend to make challenges in the campaign mode.

I would think Alliance Party. An alliance event where every minute 3 boxes appear in a room. You collect the contents by standing next to the box. The boxes appear with a 60 second time where you have 30 seconds to collect. When timer counts down, 3 new boxes will appear. Max collection is 15. Event last 20 mins.