How to install/download darktable 3.6 via cli. Ubuntu 20.04 has only darktable 3.1

I have a dell xps 13 with ubuntu 20.04.I'm confused about how to download darktable 3.6, the latest version. If I could access it Software in ubuntu only has darktable 3.1. Mostly Software is just blank - but that's another question.

If you prefer deb-packages, then you can add the PPA to get 3.6:

sudo add-apt-repository ppa:ubuntuhandbook1/darktable
sudo apt-get update
sudo apt-get install darktable

You can install the Flatpak version of Darktable from your terminal, which is usually more up to date than in the Ubuntu repositories, or than is available on Snapcraft:

$ flatpak install org.darktable.Darktable

If this doesn't work, you can also install the program from the .flatpakref file for Darktable downloaded from the Flathub website, either double clicking it to open in Software, or by passing it to the Flatpak install command instead of org.darktable.Darktable.