http://certbot.iykpqm7jiradoeezzkhj7c4b33g4hbgfwelht2evxxeicbpjy44c7ead.onion
This site should be available to the rest of the Internet on port 80. To use certbot --standalone, you don’t need an existing site, but you have to make sure connections to port 80 on your server are not blocked by a firewall, including a firewall that may be run by your Internet service provider or web hosting provider.