boej,
I think all you have to do is to login to your router -> Firewall --> Port Forwarding and forward WAN port 443 to LAN 8123 for the IP address of your Raspberry PI (or what ever HA is running ON).
I don’t know why this is not mentioned in the add-on documentation. It claims port forwarding is not necessary.
I think 443 is the default incoming port used for https.
(Maybe there is a way to switch to port 8123 by adding 8123 to various files and forward 8123 to 8123. I have not been able to get this working.)
I had more problems to access HA internally.
I use:
https://xxxx.duckdns.org:8123
To access HA using Safari on my iPhone. I had to install the Dnsmaq Add-on with forwarding xxxx.duckdns.org to the IP address of my Raspberry PI.
here is a configuration.yaml segment. Note that I don’t use the base_url token.
http:
api_password: !secret api_password
ssl_certificate: /ssl/fullchain.pem
ssl_key: /ssl/privkey.pem