I've been following a couple of tutorials to add ssl to my server (node application).

I tried installing Certbot with the following line on by Ubuntu 20.04 server:

sudo add-apt-repository ppa:certbot/certbot

but got a warning and no install:

This is the PPA for packages prepared by Debian Let's Encrypt Team and backported for Ubuntu.                                                                         

Note: Packages are only provided for currently supported Ubuntu releases.

More info: https://launchpad.net/~certbot/+archive/ubuntu/certbot

Press [ENTER] to continue or Ctrl-c to cancel adding it.*

After searching the net, there is mention of not using PPA, but to use an earlier standalone version - also mention of using snap - But I cannot find a concrete answer. I am using Express and not nginX.

Could someone suggest how to install, please?

Update

Ran sudo snap install certbot.

Result:

error: This revision of snap "certbot" was published using classic confinement and thus may perform

   arbitrary system changes outside of the security sandbox that snaps are usually confined to,

   which may put your system at risk.

   If you understand and want to proceed repeat the command including --classic.