If you want an up to date version you can download the last one on blender.org, uncompress the archive and use it this way.

If you need Nvidia support or just always want it up to date without downloading again and again… you can use the PPA : sudo add-apt-repository -y ppa:thomas-schiex/blender && sudo apt install -y blender

You can replace  blender with blender-edge for the very last version (in current stable branch anyway)

You can install the snap “Darktable” from Ubuntu Software or use the deb PPA. Both work.

Snap in command line : snap install darktable

‼ If you want it to be able to access USB drives or other file-systems (second storage disk ?) : In Ubuntu Software, Click Authorisations then check it and close
or in command-line : snap connect darktable:removable-media

Last stable version PPA : sudo add-apt-repository -y ppa:pmjdebruijn/darktable-release && sudo apt install -y darktable

Last Unstable PPA : sudo add-apt-repository -y ppa:pmjdebruijn/darktable-unstable && sudo apt install -y darktable

If you want Gimp with the most usefull plugins, just use the PPA with this command. You will have Gimp, the plugins and G’MIC (GREYC’s Magic for Image Computing). Perfect for very “pro” jobs.

sudo add-apt-repository -r ppa:otto-kesselgulasch/gimp && sudo apt install -y gimp-data-extras gimp-plugin-registry gmic