http://bentasker.i2p/posts/blog/house-stuff/connecting-my-smart-meter-to-influxdb-using-telegraf-and-a-glow-display.html
The first is glow/<your device id>/STATE with the following information {
"timestamp":"2023-07-01T11:44:11Z",
"software":"v1.9.1",
"hardware":"GLOW-IHD-01-1v4-SMETS2",
"wifistamac":"<redacted>",
"smetsversion":"SMETS2",
"eui":"<redacted>",
"zigbee":"1.2.5",
"han":{
"rssi":-52,
"status":"joined",
"lqi":192
}
} This provides details about the Glow display itself, including the state of it's connection to the smart meter's Home Area Network .