How to create and run custom plugins for CKEditor 5 if I load it in code from the official CDN?

Question

CKEditor

Good day!

The admin area of ​​a large non-NPM project is using CKEditor 5, which is downloaded from the official CDN , and I wanted to create some plugins for the input field:

class SmartTitleUploader extends Plugin{
  init(){
    const editor = this.editor;
    
    editor.ui.componentFactory.add( 'smartTitleUploader', locale => {
            const view = new ButtonView( locale );
            ...
            view.on( 'execute', () => {} );

            return view;
        } );
  }
}
class SaveNews extends Plugin{
  init(){
    const editor = this.editor;
    
    editor.ui.componentFactory.add( 'saveNews', locale => {
            const view = new ButtonView( locale );
            ....
            view.on( 'execute', () => { } );

            return view;
        } );
  }
}

Plugins are stored in a separate js-file, and in the interface of the page with the form, when initializing CKEditor5, I attached the created plugins:

toolbar: {
    plugins: [ SmartTitleUploader, SaveNews ],
    items: ['heading', 'bold', 'link', 'smartTitleUploader', 'saveNews']
},

And when testing the launch of custom plugins in the browser, DevTools brought me the following surprises:


How to solve the problem of creating and running custom plugins for CKEditor5 if it is loaded from the official CDN and the project with it is not built on NPM?
Thanks in advance!