Welcome to the 25nd post in the randomly recurring R recitations series, or R4 for short.
A container for Ubuntu 20.04, which is itself in final beta stages, was being built while the video was made. As it is available now, we created a quick follow-up video showing the use under Ubuntu 20.04:
The updated supporting slides from the video are still at this link.
What we showed in both videos does of course also work directly on Ubuntu (or Debian, using those source repos) installations; the commands shown in the Rocker use case generally apply equally to a normal installation.