Does anyone have any idea how the in game voice chat works???? i know its there it has to be i just find it weird that a teamwork multiplayer game would only have voice chat in certain match settings

You have to go to the scoreboard, scroll down to the player, hit "A" and then out of the options "join (or)/create Fireteam with _____"

Yeah, if you can figure out how to get it to work please post your settings! I can hear friends in my fireteam but they can't hear me. I only have this problem online. It works fine in challenges and private matches.