NVIDIA container runtime error - Tensorbook

Hi, I have a new tensorbook and I am trying to setup the docker as described in the following link:

However, when I run the following section in the terminal:

Install Docker CE + nvidia-docker version 2.0

It generates the following error:

The following packages have unmet dependencies:
nvidia-docker2 : Depends: nvidia-container-runtime (>= 3.4.0) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Any idea what needs to be fixed?
Thanks.

I just updated the tutorial to work with Ubuntu 20.04.

Please follow that tutorial instead!