<script src="https://cdn.ckeditor.com/ckeditor5/23.0.0/classic/ckeditor.js"></script> code example
Example: cdn ckeditor
<script src="https://cdn.ckeditor.com/4.14.0/standard/ckeditor.js"></script><script src="https://cdn.ckeditor.com/4.14.0/standard/ckeditor.js"></script>