Once you have confirmed an order from a customer, you can now proceed to deliver this sales order.
1. To do this, click on the "Create delivery note" button from the admin screen.
2. In the pop-up that opens, you can now confirm or modify the delivered quantities. Finally, don't forget to click on Save to record the delivery and consequently reduce your stock.
If you don't have sufficient stock to deliver an order, the quantity will be shown in red. However, this is not blocking, so you can also have a negative stock value for an article.