how to copy to clipboard text area using a button javascript code example

Example 1: js copy string to clipboard

const el = document.createElement('textarea');
el.value = str;	//str is your string to copy
document.body.appendChild(el);
el.select();
document.execCommand('copy');	// Copy command
document.body.removeChild(el);

Example 2: javascript how-do-i-copy-to-the-clipboard-in-javascript

function copyToClipboard(text) {
  var input = document.body.appendChild(document.createElement("input"));
  input.value = text;
  input.focus();
  input.select();
  document.execCommand('copy');
  input.parentNode.removeChild(input);
}