This is Gimp 2.10 so the plugin is expected to be executed by Python V2. But Python V2 is deprecated since 2020, so many distros (including Ubuntu) have
1. removed Python from the default install (but it can still be installed)
2. removed the Python support in Gimp (package gimp-python IIRC).
#1 is easy to fix by installing the Python v2 package. #2 may require to steal some debs from an earlier distro (Ubuntu 19.10 was probably the last to have it). See here.
Other ways to have the Python support is to install a flatpak distro (link in the Downloads page on Gimp.org), with some more hints here.
And as I heard there is also an AppImage.
(*) Gimp 2.99/3.0 will have Python v3 support, but current Python support is still too incomplete for many scripts.
1. removed Python from the default install (but it can still be installed)
2. removed the Python support in Gimp (package gimp-python IIRC).
#1 is easy to fix by installing the Python v2 package. #2 may require to steal some debs from an earlier distro (Ubuntu 19.10 was probably the last to have it). See here.
Other ways to have the Python support is to install a flatpak distro (link in the Downloads page on Gimp.org), with some more hints here.
And as I heard there is also an AppImage.
(*) Gimp 2.99/3.0 will have Python v3 support, but current Python support is still too incomplete for many scripts.