inter.js

gistfile1.txt

var data = JSON.stringify({
  "from": {
    "type": "user",
    "id": "gnujoow.kim@gmail.com"
  },
  "body": "Hey"
});

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === 4) {
    console.log(this.responseText);
  }
});

xhr.open("POST", "https://api.intercom.io/messages");
xhr.setRequestHeader("content-type", "application/json");
xhr.setRequestHeader("cache-control", "no-cache");

xhr.send(data);