JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" id="insert">Insert Input</a>
<a href="#" id="focus">Focus</a>

JavaScript

// Declare Variables
var input = document.createElement('input'),
    insertButton = document.getElementById('insert'),
    focusButton = document.getElementById('focus');

// Apply the input attributes
 input.setAttribute('id', 'test');
 input.setAttribute('type', 'text');
 
// When #insert is clicked
insertButton.onclick = function(){
   alert("click");
   document.body.appendChild(input);
};
 
// When #focus is clicked
focusButton.onclick = function(){
   document.getElementById('test').focus();
};