Meshmatic can export your LODs for Unity. If after you import the FBX file into Unity the game engine doesn't automatically assign the LODs to the model, check if "Save LODs in single file" by following these steps:
- Follow the regular import process
- After selecting your profile, click on the edit icon to access advanced tools
- Under "Profile Options", go to the LOD section
- Ensure "Save LOD's in a single file" is checked