JSFiddle - React, Tailwind, and code Playground

HTML

<input id='cmd' size="25" style="font-size:14pt;"/>
<button onclick='performOperation()'>Enter</button>

<div class="Typewriter">
<txt id='output'></txt>
</div>

JavaScript

function performOperation(){
  if(cmd.value.toLowerCase()=='cls')
    document.getElementById('output').innerText ='';
  else
  	document.getElementById('output').innerHTML += cmd.value + "<br/>";
}