Can I Open Port 443 on my MacMini without using the Server App? I'm using an AT&amp;T router where I have port 443 open. I did a port scan and it does not show 443 open. I have the firewall open with all the default options listed that Allow incoming connections.

I'm using Let's Encrypt on my development MacMini server for my SSL certificates. I'm having a problem with accessing my website. I contacted the Let's Encrypt forum and was told that my problem was that port 443 was blocked.

This is the only option that I found so far that claims to force open a port. This solution is three years old. I'm not familiar with netcat so I'm reluctant to use it without more understanding on how this works?

How to force open TCP 443 on my machine?

I've also read several solutions that use the Server app. I'm not using the Server app because I had problems with it a while ago. Is there another clean option to turn this port on that does not use it? I'll install it if I need to but I prefer another option if one is available.

UPDATE 03/13/2019: I just installed the latest version of macOS Server to try and open port 443. The vast majority of features that were available in older versions of the Server app have been removed so I need to find another option to get this done.
"443... connected. Unable to establish SSL connection" means that the problem isn't related to port 443 being blocked; your version of wget is probably stale (see this StackOverflow post.) 

Try curl instead: curl https://mydomain.com

(Note: the "https://" part is important!)