As you are on a Mac, it will be in
~/Library/Application Support/SketchUp 2023/SketchUp/Plugins
Note the tilde ~ at the front - that’s a shortcut for your home folder.
That’s a different folder from
/Library/Application Support/SketchUp 2023/SketchUp/Plugins
The 2024 plugins will be in the corresponding folder with 2024 instead of 2023.
To see these folders, open Finder, and select Go from the menu, then Go to folder, then type or paste in the path above.
PS. If you are still using Sonoma 14.0 as your profile says, you should update to 14.4x - that prevents the crash in 2023 when applying materials.