My friend can join my server by copying my IPv4 address and it works. Turned on Subnautica.exe without Epic Games and launched multiplayer and join game, game world would be hosted.
Launched Vitrox server with Hamachi on and my friend in the virtual private network. (Nexus Mod does not seem to detect Subnautica from Epic Games, not sure for steam gamers or probably my pc) Installation and location of Subnautica from Epic Games is successful.
