Call of Duty: Black Ops III

Call of Duty: Black Ops III

PEGASUS v1.59
Having trouble trying to evac
Probably a dumb question, but I'm using the mod and have evac enabled. I'm also using controller. When I look down I get a prompt to hold X then prone. So I do that then it says to confirm hit X and prone. So I do that again. But nothing happens. Not sure what I'm doing wrong. I look at my feet hold X the. Prone and have tried pressing both at once. Need help plz