trackViewedItem does not populate a product feed

I’m trying to integrate Klaviyo with a custom built website. For Viewed Product, I’m trying to follow this guide https://developers.klaviyo.com/en/docs/guide_to_integrating_a_platform_without_a_pre_built_klaviyo_integration and also included trackViewedItem as the guide stated “Calling the Klaviyo object's trackViewedItem function below will populate a product feed of recently viewed products that can be included in emails.” However, even though viewed product event worked and also sync recently viewed products into user profile, there was no product feed creation for me to use in email template. This is what a profile look like with recently viewed products display but there is no product feed for me to use: 

Here this a part of my code on Google Tag Manager for Viewed Product:
var item = {
     "ProductName": HaravanAnalytics.meta.product.title,
     "ProductID": HaravanAnalytics.meta.product.selected_or_first_available_variant.id,
     "Price": price,
     "PriceNumber": priceNumber,
     "OldPrice": oldPrice,
     "OldPriceNumber": oldPriceNumber,
     "ImageURL": HaravanAnalytics.meta.product.imageUrl,
     "URL": window.location.href,
   };

   klaviyo.push(["track", "Viewed Product", item]);
    
   klaviyo.push(["trackViewedItem", {
     "Title": item.ProductName,
     "ItemId": item.ProductID,
     "ImageUrl": item.ImageURL,
     "Url": item.URL,
     "Metadata": {
       "Price": item.Price,
       "oldPrice": item.oldPrice
     }
   }]);