E: Package 'python-virtualenv' has no installation candidate while using Certbot to renew certificates

We had an old Ubuntu 14 server, on which we install certbot and let's encrypt certificates for SSL. Then we upgraded the server to ubuntu 20.

Since then, whenever I try to renew or generate new certificates using sudo certbot --apache or the renew command, I get this error:

Bootstrapping dependencies for Debian-based OSes... (you can skip this with --no-bootstrap)
Hit:1 http://us-west-2.ec2.archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://us-west-2.ec2.archive.ubuntu.com/ubuntu focal-updates InRelease                                
Hit:3 http://us-west-2.ec2.archive.ubuntu.com/ubuntu focal-backports InRelease                              
Hit:4 https://download.docker.com/linux/ubuntu focal InRelease                                                                             
Hit:5 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal InRelease                                                                       
Hit:6 http://ppa.launchpad.net/ondrej/php/ubuntu focal InRelease                       
Get:7 http://security.ubuntu.com/ubuntu focal-security InRelease [114 kB]
Fetched 114 kB in 2s (72.8 kB/s)   
Reading package lists... Done
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'python-is-python2' instead of 'python'
Note, selecting 'python-dev-is-python2' instead of 'python-dev'
Package python-virtualenv is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'python-virtualenv' has no installation candidate

I have tried endless forums and tricks including this top google hit -> https://stackoverflow.com/questions/62314556/how-to-install-virtualenv-on-ubuntu-20-04-gcp-instance, but no luck yet :( Any ideas?