/**
 * @param array $fields
 * @return array
 */
add_filter('site-reviews/review-form/fields', function ($fields) {
    foreach($fields as &$field) {
        if ('rating' === glsr_get($field, 'type')) {
            $field['class'] = 'glsr_trx_addons_attrib_rating';
        }
    }
    return $fields;
}, 20);