TAO classification /bin/sh: 1: pip3: not found

Hi I am working on the Pascal VOC tutorial jupyter notebook and have downloaded and unpacked the VOCdevkit package.

The next cell is:

install pip requirements

!pip3 install tqdm
!pip3 install matplotlib==3. 3. 3

when the cell is run it returns:
/bin/sh: 1: pip3: not found
/bin/sh: 1: pip3: not found

I have tried
$ sudo apt-get remove python3-pip
(from outside the notebook) and then
$ sudo apt-get install python3-pip
which confirmed pip3 was there, then removed, then reinstalled
I then tried ‘run all cells above’ and ‘run cells’, but the problem persists

I suspect that pip3 may need to be made visible to docker via an entry point but there do not seem to be any instructions on how to do this in the user guide or the docker post-installation steps.

I haven’t found any other mention of this on the forum. Could someone offer some advice please?

CUDA Version 11.6 with Ubuntu 18.04 on a dual boot ASUS ROG laptop (GTX 3080).

Thank you