Installed Duckdns, set port forwarding and all works fine external. Trying to use the https://name.duckdns.org internally I get a 403 error via Safari and a “log in” prompt with Chrome with an eventual “unable to connect” . Can access internally with https://ip_address:8123 fine however with web browser, but cannot access the front end with mobile devices and the phone app.
Apparently ios devices won’t let you connect by accepting that the certificate does not match. That’s a restriction of ios devices and nobody has posted a workaround that I’ve seen.
Any reason you can’t just use the duckDNS address from inside the network?
I just installed the dnsmasq add on. To map the duckdns server to the hassio server. Works fine now with mosquito mqqt and owntracks. Everything is referenced via the external duckdns server address. IOs app works fine just reprinted my router dns to the pi dns server 1st then the ip. Provider dns server 2nd.
If your router does not support nat loopback, adding dnsmasq to raspberrypi is the solution.
When accessing within the home network you have to add a :8123 at the end of the url though. So ios notications with attachments will work differently when home or not. The image dedicated to not_home ( xxxx.ddns.net/local/image.jpg ) will show blank if you are home. You have to use ( xxxx.ddns.net:8123/local/image.jpg ) for it to work. You have to add new automations for each case.