Accepting JSON post

I am attempting to ‘post’ JSON using this, but nothing is appearing on the destination page. Can you let me know what I am missing? Thx.

function makeJSON_(object, options) {
  if (options.format == FORMAT_PRETTY) {
    var jsonString = JSON.stringify(object, null, 4);
  } else if (options.format == FORMAT_MULTILINE) {
    var jsonString = Utilities.jsonStringify(object);
    jsonString = jsonString.replace(/},/gi, '},\n');
    jsonString = prettyJSON.replace(/":\[{"/gi, '":\n[{"');
    jsonString = prettyJSON.replace(/}\],/gi, '}],\n');
  } else {
    var jsonString = Utilities.jsonStringify(object);
  }
  if (options.language == LANGUAGE_PYTHON) {
    // add unicode markers
    jsonString = jsonString.replace(/"([a-zA-Z]*)":\s+"/gi, '"$1": u"');
  }
  return jsonString;
}

var JSON_DESTINATION_URL = 'https://rpssolar.com/?page_id=1822';

function sendJson_(json) {
   var options =   {
     "contentType":"application/json",
     "method" : "post",
     "payload" : json
   };