Hi,
You should have fmodstudio.bundle and fmodstudioL.bundle in the Assets/Plugins/FMOD/lib/mac folder in your Unity project. If they are not there, you may need to reimport them from the FMOD for Unity package.
If they are there, select fmodstudioL.bundle and check the import settings in the Inspector. They should look like this:
If the import settings are correct, fmodstudio.bundle and fmodstudioL.bundle should be copied to (your built app bundle)/Contents/Plugins when you build the game.
If none of this helps, please let us know and we’ll investigate further.