insert clipboard content into a javascript code example

Example 1: javascript text to clipboard

function copyToClipboard(text) {
   const elem = document.createElement('textarea');
   elem.value = text;
   document.body.appendChild(elem);
   elem.select();
   document.execCommand('copy');
   document.body.removeChild(elem);
}

Example 2: how to access clipboard via js

navigator.clipboard.readText().then(clipText =>
  document.getElementById("outbox").innerText = clipText);