If the barcode doesn't return values for your product, enter the name and nutritional information yourself and log the entry as you normally would. Logging it saves that barcode to your own food database, so scanning it again afterward should pull it up automatically.

The nutritional information of product often changes as they adjust portion sizes, ingredients, etc. After you scanned a product, change the values of the macros to match those listed on the food item, then any future scans of that barcode should return your updated values. Change values once, have it fixed forever.