It wasn't obvious to me from the README what this is.<p>Let's Encrypt (or more generally, any certificate authority implementing the ACME protocol) can authenticate (verify ownership by doing something only the owner of the domain can do) the domain for which it issues certificates using various methods, one of them being adding a temporary DNS TXT record. Certbot (the ACME client) is responsible for doing the client-side part of the authentication, in this case adding the DNS TXT record via this plugin.<p>The certbot DNS plugins are specific to a particular DNS server software or hosting provider's DNS service. For examples, see certbot-dns-* at [1]. This one is specific for software called "Acme DNS Server" [2].<p>> Acme-DNS is a small DNS server with the sole purpose to handle ACME DNS challenges. This is a great way to automate your challenges without the support of your DNS provider.<p>[1] <a href="https://github.com/certbot/certbot" rel="nofollow">https://github.com/certbot/certbot</a><p>[2] <a href="https://github.com/gridworkz/kubernetes/wiki/Acme-DNS-Server" rel="nofollow">https://github.com/gridworkz/kubernetes/wiki/Acme-DNS-Server</a>