Hi @richardmaps!
Within Rapidweaver… Hold down the Option key and choose Reveal Addons Folder from the View menu.
The Reveal Addons Folder item will only appear in the menu when you are holding down the Option key.
Also… here is the path that will open up for you:
~/Library/Containers/com.realmacsoftware.rapidweaver6/Data/Library/Application Support/RapidWeaver