Here's how to create an invoice:

1. Go to Invoices and open "New Invoice"
2. Select a customer or add one from the customer picker
3. Add the line items with description, quantity, price, and VAT
4. In the Invoice Details card, set the invoice date and due date
5. Use "Save as Draft" if it is not ready yet, or "Finalize" when the invoice is ready
6. After saving, open the invoice detail page to preview or send it

Tip: Company defaults like numbering, payment terms, and PDF settings live under Company.