JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-2.2.4.min.js"></script>
<textarea rows="10" cols="20" id="result">

JavaScript

function validarRut(value){
	var promise = new Promise();
  $.ajax({
    type: "get",
    url: "/",
    success: function(response){
      promise.resolve(response);
    },
    failure: function (response) {
      promise.reject(response);
    }
  });
  return promise; 
}

function buscarEmpresa(textBox) {
  var res;
  validarRut(textBox.value).then(function(res){
    if (res) {
      textbox.text(res.toString());
      // do whatever you want with the result
    }
  })
}

$(document).ready(() =>{
	buscarEmpresa($('#result'));
})