optoctreepatch file to:

\SteamLibrary\steamapps\common\Subnautica\BepInEx\plugins\TerrainPatcher\patches




structure file to: 

\SteamLibrary\steamapps\common\Subnautica\BepInEx\plugins\EpicStructureLoader\Structures

you need: 

- EpicStructureLoader
- TerrainPatcher