Invoicing is automatically linked to stock. Go under Finances - Invoices - New invoice, the view for creating a new invoice appears. Enter all relevant data of your invoice as usual.
At step #4, you can add your desired positions where you can also "Warehouse" area is available. After selecting a product, you can see here in which warehouses your product is available. In addition, the available quantity of the product in the respective warehouses is also indicated.
Also select the quantity of each product to be charged for your invoice.
If the quantity falls below the minimum stock stored for the product or the available quantity, a message will appear immediately. This supports efficient merchandise management, since you can make a new purchase immediately after the invoice has been generated in order to top up the necessary product again.
The stock is automatically reduced after the invoice has been created.