How to start a game on Steam and invite a Nintendo Switch player?

[superperforat0r]

I see you can invite friends to a game, but only steam friends on steam and switch friends on the switch, but
is there a way to start a game with steam, then invite a player that is playing on a Switch?
Maybe it's possible when both devices are in the same (W)LAN?
Is it possible over the internet?
Does it start a local server on the local machine?
If yes what port does it use that i have to forward on the firewall?

[Plastic Shitlord]

there is no crossplay so it's impossible to begin with

[superperforat0r]

But on the store page it says "Cross-Platform Multiplayer"

[Plastic Shitlord]

Originally posted by superperforat0r:

But on the store page it says "Cross-Platform Multiplayer"

As in Windows/Mac/Linux