Nspanel pro api

1

Hi,

I have followed the guide https://sonoff.tech/nspanelpro-api

But when I try the example they have provided for adding a device ( I already got the token), I get an this error:
This is the request:

{
  "event": {
    "header": {
      "name": "DiscoveryRequest",
      "message_id": "8cd0bcb1-8ff3-400f-8a9e-8cdab32907508",
      "version": "1"
    },
    "payload": {
      "endpoints": [
        {
          "third_serial_number": "34923849283429839",
          "name": "my plug",
          "display_category": "plug",
          "capabilities": [
            {
              "capability": "power",
              "permission": "readWrite"
            }
          ],
          "state": {
            "power": {
              "powerState": "on"
            }
          },
          "manufacturer": "Demo",
          "model": "Demo model",
          "firmware_version": "1.0.0",
          "service_address": "https://httpbin.org/post"
        }
      ]
    }
  }
}

This is the response

{
	"header": {
		"name": "ErrorResponse",
		"message_id": "8cd0bcb1-8ff3-400f-8a9e-8cdab32907508",
		"version": "1"
	},
	"payload": {
		"type": "INVALID_PARAMETERS",
		"description": "invalid parameters."
	}
}

Any idea what it could be