After you have set up and saved your invoice settings, the fastest and easiest way to issue an invoice is directly inside Calendar:
In Calendar, click on the reservation for which you want to issue an invoice.
When a small window pops up, click on Invoice.
An invoice with all items is displayed. Now you can edit existing items or add new ones.
If you save an invoice as a Draft, you can edit, change or delete it afterwards.
When an invoice is issued, it is not possible to further change it. You can only cancel it and create a new one if you need to make additional changes.
When previewing a draft or an issued invoice, you can immediately print it or save it as a PDF file:
You can reach your issued, canceled or drafted invoices and everything else related to invoices by clicking on Invoices in the main menu: