Cannot download any book

[lorenzoFabbri]

I am using the latest version of the plugin with Calibre 7.23 on macOS.

From the screenshot above you can see that the book is available but when I right-click on it the "Download" option is not clickable. Is this a bug or I do not understand how it works? Thank you.

EDIT:

Apparently some books cannot be downloaded but others yes (the "Download" option is clickable). The problem is that a pop-up window appears saying that the book will be downloaded and added to the library automatically, but once it's finished the book is not there.