$ website="my_website123.com"
  $ sudo certbot certonly --standalone -d $website -d www.$website --email admin@$website
  Saving debug log to /var/log/letsencrypt/letsencrypt.log
  Plugins selected: Authenticator standalone, Installer None
  Starting new HTTPS connection (1): acme-v01.api.letsencrypt.org
  Cert not yet due for renewal

  You have an existing certificate that has exactly the same domains or certificate name you requested and isn't close to expiry.
  (ref: /etc/letsencrypt/renewal/www.my_website123.com.conf)

  What would you like to do?
  -------------------------------------------------------------------------------
  1: Keep the existing certificate for now
  2: Renew & replace the cert (limit ~5 per 7 days)
  -------------------------------------------------------------------------------
  Select the appropriate number [1-2] then [enter] (press 'c' to cancel): 2
  Renewing an existing certificate
  Performing the following challenges:
  http-01 challenge for my_website123.com
  http-01 challenge for www.my_website123.com
  Waiting for verification...
  Cleaning up challenges

  IMPORTANT NOTES:
   - Congratulations! Your certificate and chain have been saved at:
     /etc/letsencrypt/live/www.my_website123.com/fullchain.pem
     Your key file has been saved at:
     /etc/letsencrypt/live/www.my_website123.com/privkey.pem
     Your cert will expire on 2018-10-18. To obtain a new or tweaked
     version of this certificate in the future, simply run certbot
     again. To non-interactively renew *all* of your certificates, run
     "certbot renew"
   - If you like Certbot, please consider supporting our work by:

     Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate
     Donating to EFF:                    https://eff.org/donate-le