To generate an invoice from a receipt, go to:
Finance > Sales and listings > Receipts.
You will see a list of all generated receipts, including those that have been paid, those that remain unpaid, and any refunds.
To open the receipt from which you want to generate an invoice, click the green icon on the right-hand side. This will open the Sales Receipt Details screen.
Once you are in the receipt details screen, scroll to the bottom of the page and click Generate Invoice.
The system will automatically create an invoice using the information from the selected receipt, converting it into an invoice in a single step.