certbot certonly --manual -d example.org
This will obtain a SSL certificate for
example.org in manual mode. Manual mode means you have to create an ACME challenge file manually. Having this option is nice, because you don’t need to run certbot one the machine that handles the specified domain.
I had to figure out how to obtain a SSL certificate for a good ol’ website that only has FTP(S) access and no certbot installed.
Caveat: letsencrypt certificates are issued for 90 days only.