I am trying to configure the iOS app. I have successfully set up DuckDNS subdomain with Let’s encrypt certificate. So the home assistant is accessible through https://homeassistant.local:8123 on the local network and https://my-domain.duckdns.org:8123. The problem with the app is that when submitting the local address in the app configuration I get the “Invalid certificate” error. On the web browser I can bypass this error but it is not possible within the app. On the external network everything works fine.
How to solve this error? I have quite a basic WiFi router, without even possibility to input my own DNS servers.