chat.postMessage method working script using JavaScript

chat.postMessage.js

const request = require('request');

let token="xoxo-xoxo";
let channelid="C00LR00M";
var url = "https://slack.com/api/chat.postMessage";
var auth_token = token; //Your Bot's auth token
var headers = {
   "Authorization": "Bearer " + auth_token,
   "Content-Type" : "application/json"
}
var body = {
    channel: channelid, // Slack user or channel, where you want to send the message
    text: "It's a nice day to chat!"
}
request.post({
   "url": url,
   "headers": headers,
   "body": JSON.stringify(body)
}, (err, response, body) => {
   if (err) {
       reject(err);
   }
   console.log("response: ", JSON.stringify(response));
   console.log("body: ",body);
});