Works on Opencart / OcStore 3.x. and Opencart 2.3 (including their various builds).
CKEditor 4.21 + Extended Filemanager replaces the standard Summernote editor throughout the system, as well as in third-party extensions (with few exceptions)

DEMO - https://php-nginx.ru/demo/admin
login:demo
pass:demo

CKEditor is a popular WYSIWYG HTML editor, often used in CMS Opencart to replace the standard Summernote.
Flexible, functional, extensible with plugins, time-tested.
Add-in allows you to replace the standard and not useful editor Summernote.

In addition to the standard plugins included in the full package, added:
Autosave (will allow you not to lose data when you "drop out" of the admin panel or accidentally reloading the page. Runs once every 30 seconds (uses LocalStorage). Writing data to the database site occurs only after clicking on the button "save");
CodeMirror (syntax highlighting);
Font Awesome;
auto-links (automatically makes the inserted text-link a real link);
word count;
Keep TextSelection (keeps text selected when switching between WYSIWYG mode and code mode);
insert video from Youtube;
The add-on uses its own file manager (FM) created on the basis of Opencart's standard FM.
If you need to integrate some other file manager into ckeditor - this service is performed for a fee and if technically possible. If you have add-ons that modify standard file manager and you want them to be supported, then this work is also performed for a fee.

File manager specific:
multi-loading of images
"breadcrumbs" for easy movement through folders;
last folder in memory;
transliteration of Cyrillic characters in file names;
replacement of invalid characters in file names;
ability to enable uploading and pasting of other file types (not only images) that are specified in the main settings of the store;

Usage rules: one domain - one purchase. Otherwise, I withdraw my support obligations.