Flatpak-installed Calibre: cannot find ebook-convert command

On my Linux Mint 22 Cinnamon (Wilma) based on Ubuntu 24.04 LTS (Noble). I ended up installing Calibre in spite my initial dislike, via Flatpak:

$ flatpak install flathub com.calibre_ebook.calibre

The installation was successful, **but the the shell can't find the ebook-convert command** (official manual page link ). *** Reasoning about choosing Flatpak version: At this point of time, reading upon the changelog here: https://calibre-ebook.com/whats-new It is obvious the developer(s) are very active. The packaged version is Release: 7.6 [01 Mar, 2024], whereas the Flatpak version is the latest available (Release: 7.20 [18 Oct, 2024]). In spite, I originally have thought I would only use the ebook conversion command, this software might *surprise me*,..