Good news for the config!
Have you tried changing node-16 to your Gladys’s IP address?
And then you directly put http://192.168.X.Y:12001 (well, the correct IP of your Gladys).
EDIT: @NoiZe also had access issues with the port and was able to resolve it: Use another port for Zigbee2MQTT dashboard? - #6 par NoiZe