If you want to give access to someone in your LAN, you must not use your external/router address.
The router configuration is needed for access over the internet.
Also the "self test" is about working over the internet, you don't need it in LAN.
In LAN you must use local address. The address starting with 70 is not your local address. A local address begins with 192 or 10.
"localhost" works only on your computer, not in the LAN.