Problems using Record Upsert API when trying to check for duplicates

Problems using Record Upsert API when trying to check for duplicates

I'm trying to use the Record Upsert API and am running into problems with how to specify the proper duplicate check fields.

I'm using cURL, and can't figure out where you want me to include the `duplicate_check_fields` parameters

I tried putting it in the URL:

https://www.zohoapis.com/crm/v2/contacts/upsert? duplicate_check_fields=Contacts-Email,Last_name

And in the data, both inside and outside of the data array:


    { 
       "data":[ 
          { 
             "Company":"<COMPANY>",
             "Last_Name":"<LAST_NAME>",
             "First_Name":"<FIRST_NAME>",
             "Phone":"<PHONE NUMBER>"
          }
       ],
       "duplicate_check_fields":"Contacts - Email,Last_Name"
    }

and 

    { 
       "data":[ 
          { 
             "Company":"<COMPANY>",
             "Last_Name":"<LAST_NAME>",
             "First_Name":"<FIRST_NAME>",
             "Phone":"<PHONE NUMBER>"
          },
          "duplicate_check_fields":"Contacts - Email,Last_Name"
       ]
    }

or

    { 
       "data":[ 
          { 
             "Company":"CTM",
             "Last_Name":"<LAST_NAME>",
             "First_Name":"<FIRST_NAME>",
             "Phone":"<PHONE NUMBER>",
             "duplicate_check_fields":"Contacts - Email,Last_Name"
          }
       ]
    }

When I place it in either location in JSON the server responds with:

{"code":"INVALID_DATA","details":{"expected_data_type":"jsonobject"},"message":"body","status":"error"}

I am stumped as to what I'm missing with what should be a fairly straight forward task.