MATLAB: ThingSpeak: Problem with Bulk-Write JSON Data

Question

I am trying to use "Bulk-Write JSON Data" API to send some data to my ThingSpeak channel: https://www.mathworks.com/help/thingspeak/bulkwritejsondata.html

My channel has four fields: "Temperature", "Pressure", "Humidity", "CO2"

My POST query looks like this:

POST /channels/XXXXXX/bulk_update.json HTTP/1.1
Host: api.thingspeak.com
Content-Type: application/json
{
  "write_api_key": "XXXXXXXXXXXXXXXX",
  "updates":
  [{
    "created_at": "2018-06-21 22:21:40 +0300",
    "Temperature": "27.51",
    "Pressure": "746.02576",
    "Humidity": "42.407",
    "CO2": "978"
    }
  ]
}

But server returns response:

{
    "status": "400",
    "error": {
        "error_code": "error_bad_request",
        "message": "Bad Request",
        "details": "The request cannot be fulfilled due to bad syntax."
    }
}

What is wrong?

Answer 1

As key-value pairs of update says, key names should be created_at, delta_t, field<X>, latitude, longitude, elevation, status.

So, how about changing the field names of "Temperature", "Pressure", "Humidity", "CO2" to "field1", "field2", "field3", "field4", respectively?

{
  "write_api_key": "XXXXXXXXXXXXXXXX",
  "updates":
  [{
    "created_at": "2018-06-21 22:21:40 +0300",
    "field1": "27.51",
    "field2": "746.02576",
    "field3": "42.407",
    "field4": "978"
    }
  ]
}