The game will often show up in Steam as "Spacewar" or another free-to-play title; this is normal and necessary for the multiplayer bypass to work. Common Connection Fixes
So, you’ve built your hook, you’ve got a plastic cup to collect rain, and you’ve managed not to get eaten by Bruce for the first 20 minutes. But let’s be honest—Raft is boring alone. The magic of this game is screaming at your friend to patch the hole while you fend off the shark. Help with RAFT - multiplayer - r-PiratedGames
Copy the fix files into your RAFT game folder, overwriting the existing files. The game will often show up in Steam