I actually have an issue with one of my certs so had to use this today
certbot certificates
as you can see invalid-certbot-windows.firecube.xyz.conf is incomplete as I wasn't able to get a certificate issued
I would like to remove it and related folders so I am going to use the certbot delete command
Before Running Delete Command:
Running Command
certbot delete
Post Run:
Ignore the error at the bottom. It's to do with symlinks pointing at files that aren't there 
Another key thing to note: the names are internal certbot names not necessarily the domain names
Andrei