Hint: The Certificate Authority failed to verify the temporary nginx configuration changes made by Certbot. Ensure the listed domains point to this nginx server and that it is accessible from the internet.
Some challenges have failed.
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot with -v for more details.
You could either use a Cloudflare "origin" certificate (it's a cert that Cloudflare trusts but isn't useful for public traffic) installed on your service Origin CA certificates · Cloudflare SSL/TLS docs or you can adjust your website SSL settings in the cloudflare control panel to be less strict and allow the invalid certificate while you get Let's Encrypt setup, then put it back once you have a valid certificate.
