Unless there is a bug in the driver, that means you have a book that matches the kepub in your calibre library. The driver uses information from the library to make the changes on the device. If there is no book in the library for a book on the device, it can't do anything. When you have the device connected, calibre will show a green tick next to each book in the library that is on the device. Those you can put on shelves from calibre once you have the driver configured. See
https://www.mobileread.com/forums/sho...d.php?t=193184 for how to do the configuration.