Subnautica mods are managed with QModManager [www.nexusmods.com]. One of the devs of QModManager have written this guide for Linux[github.com] on their Github page.

You need to follow it to the letter. For example, i tried to do it with winetricks to not have to install protontricks but couldn't get that to work. Because of using x64 drivers instead of x32 wine gave a lot of warnings but it works anyway. You could also try running wine in 32bit mode.

It takes some experimenting but i think it's worth, there are just such cool mods[www.nexusmods.com] available!

If you need more help, check out the Subnautica Modding[discord.com] on Discord!