You can use the "SHOP" module for quick sales of goods and services.
You can sell some goods or services in the Shop section.
To do that you would need to:

1. Go to the relevant section (Shop).
2. Find the goods or service you need using the search or a barcoad scanner.
3. By pressing the Save option add it to the purchase order.
4. You can choose a discount or a client if needed.
5. Choose the payment method and make the payment.

You can analyze your commercial activity for the period using a date filter at the bottom right.