Let me share some information about the Cost of Goods Sold, Rabee_77

The normal process for goods you stock and sell are to use the inventory-type item. These will create COGS when sold. Then, you can choose to use non-inventory items only when the value of that stock is not significant, or if you are recording the stock value manually through accounts other than inventory.

In this case, I'd suggest consulting your accountant for other ways how to record COGS for non-inventory items. For more information on how to calculate COGS, check out this article: How To Record Cost of Goods Sold. Also, I'm adding this article to learn more about COGS: Understand Inventory Asset And Cost of Goods Sold Tracking.

Also, the option to add the products/services in the journal voucher is unavailable in QuickBooks Online. Here's an article you can refer to for more details about adding product and service items to QuickBooks Online. 

Keep me posted if there's anything else that you need about COGS. As always, we're just a few clicks away if you need further assistance.