GIMP available from the default Ubuntu repo (non-flatpak, non-ppa) lacks Python. I take it that Python-based plug-ins won’t work without this!
How can one go about adding Python, when “gimp-python” appears to have been dropped: Index of /ubuntu/pool/universe/g/gimp
Please do not close as not all of us can/will use flatpak/ppa, ex., enterprise environment limited to vetted repos.
If you’re stuck with just the Ubuntu repos, then you’re out of luck.
Get flathub vetted, or better, grab the flatpak manifest and build it yourself.
Also why not post on the existing thread?
That’s unfortunate to hear. There’s no real robust way to control Flathub or spin your own flatpak store so flatpaks are virtually off limits to any locked down enterprise network. Nature of this isn’t limited to Ubuntu repo, EPEL is the same.