title: Is there a way to install Let's Encrypt certificate on .dev domain?
body: <p>I have a Wordpress blog that is hosted on VPS using LEMP Stack (on Ubuntu 20.04). The domain (underthesun.dev) is already matched to VPS server (FTP and ping is ok, so DNS records are seem to be correct), but there is an HSTS technology that I have to bypass.
  Standard <code>certbot</code> package doesn't work here, there is an error:</p>
  <pre><code>
     Domain: underthesun.dev
     Type:   connection
     Detail: Fetching
     http://underthesun.dev/.well-known/acme-challenge/qDNw-QTDRMOGmsX8QkA_-t5gPl7ETAlPYYSzbxXznRM:
     Timeout during connect (likely firewall problem)
  
     Domain: www.underthesun.dev
     Type:   connection
     Detail: Fetching
     http://www.underthesun.dev/.well-known/acme-challenge/jzfnoaSnwOHpHr1BgrKHT82-gtaMeBUp1il9RT5dYw4:
     Timeout during connect (likely firewall problem)
  
  </code></pre>
  <p>There is not so many information about this issue. I did not get what firewall it is implied. What should I do and is it real in general to install free SSL like this?</p>
  <p>UPD: added HSTS header in Nginx config, and checked <a href="https://hstspreload.org/?domain=underthesun.dev" rel="nofollow noreferrer">via tool from Chromium</a>. But the issue is still relevant...</p>