Should be noted that http validation is used

[Mugane]

It should be noted in the docs that the SSL issuance uses HTTP for authentication, so you'll need to have your domain pointing at the server and DNS resolved before SSL certs can be issued. Also, if your target app is running on port 80 you'll need to move it to another port, otherwise the proxy won't be able to load on port 80 to do the SSL install.