To any and all looking to make a klaviyo request.

klaviyoRequest.js

var request = require("request");

var klaviyoRequest = function(data, callback){
  var dataJsonString = JSON.stringify(data);
  var dataBuffer = new Buffer(dataJsonString);
  var dataBase64 = dataBuffer.toString("base64");
  request({
      "url": "https://a.klaviyo.com/api/track",
      "qs": {
        "data": dataBase64,
      }
    }, callback
  );
}