JSFiddle - React, Tailwind, and code Playground

HTML

<input id="exNumber">

JavaScript

var observer = new MutationObserver(function(mutations) {
  mutations.forEach(function(mutation) {
    // console.log('Mutation type: ' + mutation.type);
    if ( mutation.type == 'childList' ) {
      if (mutation.addedNodes.length >= 1) {
        if (mutation.addedNodes[0].nodeName != '#text') {
//        console.log('Added ' + mutation.addedNodes[0].tagName + ' tag.');
        }
      }
      else if (mutation.removedNodes.length >= 1) {
       // console.log('Removed ' + mutation.removedNodes[0].tagName + ' tag.')
      }
    }
     if (mutation.type == 'attributes') {
      console.log('Modified ' + mutation.attributeName + ' attribute.')
    }
        });   
});
  
var observerConfig = {
        attributes: true,
        childList: false,
        characterData: false
};
  
// Listen to all changes to body and child nodes
var targetNode = document.getElementById("exNumber");
observer.observe(targetNode, observerConfig);