First, certbot can also be called letsencrypt on some machines. And, it is stored in various places, depending on how you set it up.
On a Devuan server, installed for ISPConfig, it is located in /opt/eff.org/certbot/venv/bin/certbot, so I will use that path for all the examples below. This is not in the path for any user, as far as I can tell, so you have to use the full path to call it.
A lot of this is taken from https://certbot.eff.org/docs/using.html, which is confusing and hard to use, but does give an exhaustive list of the commands at the bottom.
/opt/eff.org/certbot/venv/bin/certbot certificates
Sample output would be as follows. Note that you may have multiple entries, and not all entries will have multiple domains in them.
Saving debug log to /var/log/letsencrypt/letsencrypt.log - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Found the following certs: Certificate Name: mail.example.com Domains: mail.example.com imap.example.com smtp.example.com Expiry Date: 2020-10-26 12:09:56+00:00 (VALID: 37 days) Certificate Path: /etc/letsencrypt/live/mail.example.com/fullchain.pem Private Key Path: /etc/letsencrypt/live/mail.example.com/privkey.pem - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -