To show an image in a form, no option type is necessary. Simply add a field with the following options:
addField([ 'type' => 'imgPreview', //required 'value' => $product->result(0,'thumb_url'), 'title' => $product->result(0,'title_'.$kas['main_lang']), //optional 'alt' => 'product image', // optional 'class' => 'img_preview', //optional, img_preview by default 'id' => '', //optional, empty by default 'icon' => '<i class="far fa-image"></i>' //optional, this is the default ]);