Generate a certificate for nginx
$ sudo certbot --nginx
$ sudo certbot --nginx -d example.com
List all the certificates
$ sudo certbot certificates
NOTE: check each nginx conf files updated by Certbot
Delete a specific certificate
$ sudo certbot delete --cert-name example.com
EXPAND, add a new domain to existing certificate
$ sudo certbot certonly --expand --cert-name existingdomain -d existingdomain.com,www.existingdomain.com,new.existingdomain.com