New to this, can't figure out voice.

Heyo, first time poster. I am streaming fortnite with other friends and I can't get their voices to come through the stream. I play on Xbox and they play on Xbox and PlayStation, do they need to be in the console party chat? Or in game chat? Is there a way to make in game chat come through? I'm asking cause I'm not sure what to google and I'm not finding much.