Kirby 3.6 adding files field to plugin page

Hi,

i have try to extend the advanced panel area sample (Advanced Panel area | Kirby CMS) with an image field. In the dialogs folder is an fields.php file. When i click “add product” on the plugin page, a popup open and i see a files area. If i try to select or upload a file, i’ll get an error: Cannot read properties of undefined (reading ‘field’)

Is this a bug?

return [
    'title' => [
        'label' => 'Title',
        'type'  => 'text'
    ],
    'image' => [
        'label' => 'Title',
        'type'  => 'files'
    ],