I'd suggest to use Rich Text instead. This widget is based on TinyMCE. See the docs.
CKEditor4 is deprecated since jun 2023:
https://ckeditor.com/blog/ckeditor-4-end-of-life/
if you really need to use CKEditor, there's an option
The CKEditor 4 widget, based on the Open Source version of CKEditor 4 (4.22.1)