Xbox and PC Crossplay (And Other Systems)

Hi, I’m currently working on an FPS game. Alot of my friends, who I’d like the test and play with don’t have PC’s and only have Xbox’s. My plan for my game is to release this game on as many systems as possible. I have Direct Connect working (I give them my IP and port, and they type it in, and they can join my server. PS- This is for my PC, and it works). I also found out a way to test my game on Xbox, so that shouldn’t be an issue.

My main question is here: Is it just as easy, to give the xbox players, my IP, and they join just like pc? Or is it a whole other system to get them to “talk” to each other? And is it the same for other systems? (PS4, Mobile, etc)

I’d really appreciate the insight before I try and actually put it on Xbox, to save me some time. Thanks in advance!!!