I would like to install Netflix app on Ubuntu.
My goal is not only to watch Netflix, but to be able to download movies and watch them when I have no internet connection.
Looking at the Netflix website it seems that it is only supported for Windows 10
Is there a way to install the app on Ubuntu as well?
Impossible. Netflix is actively blocking any browsers from downloading content except for those browsers they approved (and those are all locked browsers that support and use digital rights management (DRM).
You will need Android, Windows or MAC OS to be able to download.
Using a phone for the download and then casting, or tethering it from the phone to Ubuntu seems, to/for me, to be the easiest method.