Noob needing help

Hi all,

I am hoping someone could please tell me how to get the value of a single entity into an html page loaded as a panel_iframe. I have managed to create the websocket connection using js websocket example but just need the value of entity ‘sensor.home_mains_supply’ that i’m already getting via modbus. I just want to do some formatting on the returned value.

Any help would be a godsend right now.

Cheers Mat