Image Carousel template message in LINE Messaging API

ImageCarouselTemplate.js

const functions = require("firebase-functions");
const request = require("request-promise");

const LINE_MESSAGING_API = "https://api.line.me/v2/bot/message";
const LINE_HEADER = {
  "Content-Type": "application/json",
  "Authorization": "Bearer <CHANNEL-ACCESS-TOKEN>"
};

exports.AdvanceMessage = functions.https.onRequest((req, res) => {
  return request({
    method: "POST",
    uri: `${LINE_MESSAGING_API}/push`,
    headers: LINE_HEADER,
    body: JSON.stringify({
      to: "<USER-ID>",
      messages: [
        {
          type: "template",
          altText: "This is an image carousel template",
          template: {
            type: "image_carousel",
            columns: [
              {
                imageUrl: "https://vignette.wikia.nocookie.net/line/images/b/bb/2015-brown.png",
                action: {
                  type: "message",
                  label: "Brown",
                  text: "Brown was selected"
                }
              },
              {
                imageUrl: "https://vignette.wikia.nocookie.net/line/images/1/10/2015-cony.png",
                action: {
                  type: "uri",
                  label: "Cony",
                  uri: "https://developers.line.biz"
                }
              }
            ]
          }
        }
      ]
    })
  }).then(() => {
      return res.status(200).send("Done");
  }).catch(error => {
      return Promise.reject(error);
  });
});