Its in
Act 3.
Its unlocked after completed Ollie's intro (Jericho), as the description says. You should get it after you land with the parachute.
But I noticed that story related achievements are not unlocking for me, if I am skipping cutscenes.
Also noticed if not unlocking, try press
and navigate to achievements. It helped me a few times, but sometimes in this game, I simply have to replay to unlock it. So I recommend make saves before completing quest if its related to an achievement.