Hello @Johny_Faillab!
The JSON you need to post is that one (with “Volume_Mute”)
There is no documentation about this capability but this need 2 inputs, one is the string that have the OCF resource (in this case is “mode/vs/0”) and the second is the json object to that resource.
You are using CLI? Or other application using pysmartthings? Because you will need to update something on sources to send the “execute” capability as you can seee it need 2 input and not only one.
You can check this post with all resources from Wind-free ACs: airFlowDirection / status:dead
The problem is that this capability send commands direct to the device so it depends on what is your device (for example the resource “mode” is documented on OCF docs but “mode/vs” is a Samsung proprietary capability os it doesn’t have any documentation, I’ve got this json observing the SmartThings app when it mutes the device using postman)
I wil share my device.py and capability.py when I come back to home.