JSFiddle - React, Tailwind, and code Playground

HTML

<button onclick="document.getElementById('my_span').innerHTML='press alt + W';" style="position:fixed; top:1px; right:1px;">
Clear
</button>
<span id="my_span">press alt + W</span>

JavaScript

document.addEventListener('keydown', function(e)
{
  document.getElementById("my_span").insertAdjacentHTML('beforeend', '<br><i>keydown fired: '+e.key+'</i>');
	if(e.altKey && e.which === 87)
	{
		document.getElementById("my_span").insertAdjacentHTML('beforeend', '<br>combitation detected');
	}
}); 

document.addEventListener('keyup', function(e)
{
  document.getElementById("my_span").insertAdjacentHTML('beforeend', '<br><i>keyup fired: '+e.key+'</i>');
	if(!e.altKey)
	{
		document.getElementById("my_span").insertAdjacentHTML('beforeend', '<br>combitation stop');
	}
});