Adding a book cover without adding to my library

Back in January I sent out book giveaway boxes with my book and as an extra, the backstory of one of my characters. One of the recipients emailed to ask if I had cover art for the backstory as they were uploading it into the LT catalogue manually.

I didn't at the time, but now I do.

Except there isn't a place to add/replace a cover on the entry she made. A bit of digging around led me to believe that you had to add the book to your library to be able to upload a cover, so I added it manually with the exact same title/info as this other reader. But it made a duplicate listing without her review or the other information she had catalogued for it.

How do I add a manual entry to my library without making a duplicate?

Alternatively, how do I add a cover to an entry that was manually entered by someone else?

This is the entry in question: https://www.librarything.com/work/29712309

Since I'm now sharing the story online, it'd be nice to direct people somewhere that they can review it since it's not on Amazon or other such places.

Thank you for any help or advice!

The two works needed to be combined.

>2 lilithcat: Thank you! That helped, got it sorted!

>2 lilithcat: Is there a way to do this if there is _not_ yet an entry with a cover?

>4 marc.slingerland: It would be exactly the same process of adding the book to your own library as outlined above without worrying if it got combined to the other work properly