how to add html into javascript object code example

Example 1: how to add elements in javascript html

//adding 'p' tag to body

  var tag = document.createElement("p"); // <p></p>
  var text = document.createTextNode("TEST TEXT"); 
  tag.appendChild(text); // <p>TEST TEXT</p>
  var element = document.getElementsByTagName("body")[0];
  element.appendChild(tag); // <body> <p>TEST TEXT</p> </body>

Example 2: js create tag

//create div
let div = document.createElement('div');
//create button
let button = document.createElement('button');