whatsapp-web-dev-console-sendMessage

console.js

function sendMessage(msg){

  var msgInput = document.querySelector("#main > footer > div > div.input-container > div > div.input");
  var sendButton = document.querySelector(".icon.btn-icon.icon-send");

  var typeEvent = document.createEvent("TextEvent");
  typeEvent.initTextEvent ("textInput", true, true, window, msg, 0, "en-US");
  msgInput.focus();
  msgInput.dispatchEvent(typeEvent);


  do {
    var sendButton = document.querySelector(".icon.btn-icon.icon-send");
  } while(!sendButton)

  var clickEvent = new MouseEvent('click', {
    'view': window,
    'bubbles': true,
    'cancelable': true
  });
  sendButton.dispatchEvent(clickEvent);
}