How to reference the HTML DOM using Animate Canvas.

Google Chrome javascript console says,

Uncaught (in promise) DOMException: Document is not focused.

Looks as if there is a security update in browsers to prevent dynamically writing to the clipboard.

Here's the code I cannot get to work.

This is in the javascript file Animate produces with Canvas. 

				function copyStringToClipboard (str) {
				 const el = document.createElement('textarea');
  el.value = str;
  document.body.appendChild(el);
  el.select();
  el.setSelectionRange(0,999999999999);
  document.execCommand('copy');
  document.body.removeChild(el);
				 }

use document.getElemtnById()