product quickview

$build['quickview'] = [
  '#type' => 'link',
  '#url' => Url::fromRoute('mymodule.product_quickview', ['commerce_product' => $entity->id()]),
  '#title' => $this->t('Quick view'),
  '#attributes' => [
    'class' => ['use-ajax', 'button', 'button--small', 'button--check-stock'],
    'data-dialog-type' => 'modal',
    'data-dialog-options' => Json::encode([
      'dialogClass' => 'ui-dialog--wide ui-dialog--centered-title ui-dialog--product-stock-levels',
      'width' => 1000,
    ]),
  ],
];

mymodule.product_quickview:
  path: '/product/quick-view/{commerce_product}
  defaults:
      _entity_view: commerce_product.quickview