JSFiddle - React, Tailwind, and code Playground

HTML

<button id="btn">pew</button>

JavaScript

btn.onclick = ()=>{
  var el = document.createElement('textarea')
  el.textContent = getTimeStr()
  el.style = "position: absolute; left: -999px; bottom: 0; width: 300px;";
  document.body.appendChild(el)
  el.select()
  document.execCommand("copy");
}


function getTimeStr(){
	return new Date().toLocaleString()
}