sudo certbot renew --dry-run
Category: letsencrypt
Another instance of Certbot is already running (Letsencrypt)
If it is not running, check whether there are .certbot.lock files in your system.
find / -type f -name ".certbot.lock"
If there are, you can remove them:
find / -type f -name ".certbot.lock" -exec rm {} \;
Add a command to list all certificates currently installed and their domains (Letsencrypt)
sudo certbot certificates
Letsencrypt
sudo certbot -i apache -a webroot -w /var/www/example.com/public_html -d example.com -d www.example.com