How can I get cross platform Fortnite party chat in my Twitch stream?

I have been attempting to stream for two years now straight from my Xbox, but it’s frustrating that my viewers can’t hear my game chat. We cannot use Xbox party chat, as my friends play on pc or PlayStation. I have checked all settings on Xbox, fortnite and twitch. This seems to only be an issue for Xbox users since all of my stranger friends on pc and PlayStation have no issues and don’t have to do anything to get their game chat in stream. Please help or I may have to switch platforms.

:)