fix : fix goods detail page google gtm

app/design/frontend/Joshine/breeze/Magento_Catalog/templates/product/view/details.phtml

@@ -57,7 +57,7 @@ $product = $objectManager->get('Magento\Framework\Registry')->registry('current_
         'event': 'view_item',
         'event': 'view_item',
         'value':  '<?= $product->getFinalPrice() ?>',
         'value':  '<?= $product->getFinalPrice() ?>',
         'items': [{
         'items': [{
-            'id': <?= $product->getSku() ?>,
+            'id': '<?= $product->getSku() ?>',
             'google_business_vertical': 'retail'}]
             'google_business_vertical': 'retail'}]
     });
     });