Where is "downloads" folder in Calibre-Web?

I’m trying to get Calibre-Web working. The Umbrel store says to make my library be /books, but that’s just in the root of Calibre-Web’s Docker container.

I have an existing Calibre library made with the Calibre desktop app that I’ve uploaded to downloads/books in the Files app, same place that apps like Plex, Jellyfin, Autiobookshelf, etc. have access to.

Where is the downloads directory mounted in Calibre-Web, or is it even mounted in its container at all?

Thanks, community!