If i understood correctly, cross play for us linux gamers should now be available, but apparently i can't play with this friend of mine that has the game from Epic Games Store on Windows except through "Play by Cloud" which is incredibly slow way to play since game has to pass whole save files and reload them every pass of turn

His version has "join codes" to join other people's games, i have them only in "Play by Cloud". Creating an Internet game won't appear in the other's list of internet games, and our lists of internet games are different, very few times we found a game with same game name on both our screens and anyway we couldn't make it in time to join in it together. I'm wondering what would happen if a Windows Steam version would invite me and give my friend the join code, but i couldn't try this since i don't know anyone with Windows Steam version.

Probably a way to avoid this problem would be install windows version of the game through Proton but i have tried and all i could see starting the game is grey screen, i searched about this problem but i didn't find any solution.

Does anyone know a way to make me play civ6 with my friend at a decent speed without me installing windows or he buying Steam version of the game?