You can send invoices directly to your customers from QuickBooks Commerce. When the sales order is Finalized, you can create a manual invoice or to automatically create one.
QuickBooks Commerce will generate an invoice accordingly.
To send an invoice to a customer via Email
You can edit the email accordingly and email it to yourself using the cc field.
Click 'Send' and your customer will receive an email of the invoice.
To Print or Save Invoice document
Select Print or Preview and QuickBooks Commerce will generate the Invoice document as follows: