Once you have the Sharing Cart plugin installed, you have to go "load" items into it from where they are currently located, then go to the course where you would like to have a copy, and extract them from the cart into the new location.
There is no such thing as a 'load' button ...
I tried with boost and Fordson theme, same result.
Addition: Got it now!
I didn't realize I have to do the 'load' from the edit menu of the very item.
Thx!! 🙏
Sorry, bad choice of words. The "edit" menu was mentioned in my last post and I should have referred to it as it has been a few days since then.