YourControls is an external mod for MSFS2020 to allow for shared cockpit flying.
Check it out on GitHub or join the Discord!
This tool checks if your device is open for connection on port 7777.
Usage: Start the YC-server on your device, then reload the page.
Does not work if you are using a VPN- or tunneling service, a proxy,
or if you changed the default port!

Test result:

Your IPv4:
is not open for connection on port 7777!

Your network configuration does not seem to allow any incoming connection on port 7777.
Check your router and firewall settings. More info on port forwarding in this knowledgebase.

If there is no possible way for you to setup the correct firewall configuration,
due to restricted access to firewall management or DS-Lite internet connection,
you can still try to setup connection with a VPN-tunnelling service like Hamachi or Zerotier.
More helpful links:
Video tutorial on portforwarding
Video tutorial on setting up Hamachi
Simple UPnP Portmapper on Github