[SOLVED] Laravel Backpack 6 ckeditor 5 view source button

I'm using backpack 6 with ckeditor 5... How do I add the 'view source' button onto the ckeditor navbar?

and also allow div and class tags to be added in the wysiwyg without them being stripped out?

i've tried installing it using: npm install @ckeditor/ckeditor5-source-editing and then using it in the field with:

$this->crud->addField([
    'name' => 'body',
    'type' => 'ckeditor',
    'extra_plugins' => [
        'source-editing',
    ]
]);

but it can't find it

plugincollection.ts:396 Uncaught (in promise) CKEditorError: plugincollection-plugin-not-found {"plugin":"source-editing"}

any help would be great, ta