I'm using CKEditor 5, and I want to install an additional plugin, 'source editing', but as far as I try, it doesn't work out for me. If I use CKEditor without additional plugin, then everything works as it should, but when I try to register the source editing plugin, I get the following error:

My code:

const ClassicEditor = window.ClassicEditor = require('@ckeditor/ckeditor5-build-classic');
const SourceEditing = window.SourceEditing = require('@ckeditor/ckeditor5-source-editing');
ClassicEditor
        .create(document.querySelector('#editor'), {
            plugins: [SourceEditing], // <--- Trying to add a plugin to a build
            toolbar: ['sourceEditing'] // <--- Trying to add a plugin to a build
        })
        .then(editor => {
            console.log(editor);
        })
        .catch(error => {
            console.error(error);
        });

The versions of SourceEditing and CKEditor are the same.