Is it possible to use field names on the Rest APIs?

Hi 

Is it possible to use field names on the RestAPIs, similar to the XML option? 
Quickbase API Portal

For the xml option you are able to use field names as follows: 
> Field names are nearly identical to field labels; if you know the field label, you can determine the field name by converting all characters to lowercase and replacing all non-alphanumeric characters (including spaces) with an underscore.

When I attempt this with the Rest as below for example: 

{
  "to": "br2shmsne",
  "data": [
    {
      "first_name": {
        "value": "This is my text: First Name 1"
      }
    }
  ],
  "fieldsToReturn": [
    "24"
  ]
}

the error is always



------------------------------
Melissa Palmer
------------------------------