DuckDNS with NGINX

I followed the instructions to setup DuckDNS with Nginx to allow remote access to Home Assistant.

I have not had any success.  Since this was written almost a year ago, I wonder if there are any additional steps that need to be done that wasn't the case when this was written?  Anyone else had success with this or any helpful ideas?

I found out that my ISP has Carrier Grade NAT.   DuckDNS will not work with this.  I believe my options are to either request a static IP address from my ISP or use the cloud based service, Nabu Casa.