If you have changed the image of your products or made any change to price, inventory, title, the barcode, etc. Then all you have to do is to click on "Sync Store Product" then a dialogue box will appear containing list of fields to be Sync with Shopify. From there you can select the fields that you want to Sync from shopify store. Then click on Sync. After this, all the changes that are made on Shopify store will be reflected on our app and after uploading the products the changes will be reflected on Walmart.com.