To require ACE in your missions, usually adding some ACE unit or vehicle should add some ace_*** addons to your mission.sqm addons and addonsAuto arrays, and therefore require ACE before being able to join the mission at all.

However, to make 100% sure the mission requires ACE, please add the "Require ACE" module logic. (Classname "ACE_Required_Logic")

Also see the ACEify_Missions tool.