request.js

function sendTimeMapRequest(geocodingResponse) {

  // The request for Time Map. Reference: http://docs.traveltimeplatform.com/reference/time-map/
  var coords = geocodingResponse.features[0].geometry.coordinates;
  var latLng = { lat: coords[1], lng: coords[0] };

  var request = {
    departure_searches: [{
      id: "first_location",
      coords: latLng,
      transportation: {
        type: "public_transport"
      },

      departure_time: departureTime,
      travel_time: travelTime
    }],

    arrival_searches: []
  };

  var xhr = new XMLHttpRequest()
  xhr.addEventListener("readystatechange", function () {
    if (this.readyState === 4) {
      drawTimeMap(mymap, this.response);
    }
  });
  xhr.open("POST", "https://api.traveltimeapp.com/v4/time-map")
  xhr.setRequestHeader("X-Application-Id", APPLICATION_ID);
  xhr.setRequestHeader("X-Api-Key", API_KEY);
  xhr.setRequestHeader("Content-Type", "application/json; charset=UTF-8");
  xhr.responseType = "json";
  xhr.send(JSON.stringify(request));
}