Flatpak implements contaninerization, which means that it hides the filesystem. This is usually good for apps that only need to open files, but for terminal applications is painful, since suddenly you don't have access to wget inside konsole+flatpak because you don't see the "outside" /usr/bin.

https://blogs.gnome.org/chergert/2019/04/25/flatpaking-terminals/ and https://gitlab.gnome.org/chergert/flatterm suggest a way of creating a terminal that can run both inside and outside of container technologies

It would be appreciated if someone that knew about konsole had a look at it. I can [try to] help with the flatpak bits.

Related:
https://invent.kde.org/teams/flathub/issues/-/issues/6
https://github.com/flathub/flathub/pull/1757