I clicked "view in my books", and went to here:
https://www.kobo.com/us/en/library.
I can click on the book there and return.
What was not obvious to me, is that in my library, I need to press the 3 periods underneath the book in "My Books". I prefer something in English. That ellipsis is not obviously a link to what I was looking for. But it had the download option. It's interesting that the Kobo chat help did not know about it. I kept looking in menus for instructions in English.