This Invoices extension allows your customers to generate an invoice for their purchase after the purchase is complete. These invoices can include complete company details, such as name, address, and tax ID, that customers can use for accounting and tax purposes.
Customers will be asked to enter the information they wish to appear on the invoice and will then be given a print friendly version of the invoice that can be downloaded or printed.
Demo: https://easydigitaldownloads.com/downloads/edd-invoices/