It shows up for "Akarnae ebook". I think showing results which let you download an epub when you search for an epub makes total sense. Kobo books are usually DRM protected and I'm not sure if it makes sense to show it to users who are specifically looking for an epub.
But either way, those results don't come from Kagi. Neither Bing nor Google show Kobo for that result, so there's no way for Kagi to show it here.