Configuration when Internet is absent

Hi, today my Internet provider is having big problems and at home the full afternoon we are without Internet.
Is my first time without Internet for such a long time with my recent smart home.

Thanks to HASS pretty much everything works well. One thing I wish to fix, basically from within my LAN some functions do not work (HA NFC Http shortcut) are those functions that have https://xxx duckdns.org as commands (with 192.168.1.2, my HASSIO host address, they do work).

How can I fix this, is it possible ? In HASS, in the host, in the router?