JSFiddle - React, Tailwind, and code Playground

HTML

<input id="text" type="text">

JavaScript

var delay = 1000,
  timer;
document.getElementById('text').addEventListener('input', function() {
  if (timer) {
    clearTimeout(timer);
  }

  timer = setTimeout(function() {
    alert('Можно отсылать')
  }, delay);
});