If needed you're able to create an invoice in your ManageByStats. Click the Create New Invoice button:
and you get a form where you can enter business info that will appear on the invoice. Below the form is a list of transactions from which you can select. Select the transactions you want to appear on the invoice.
The invoice is then generated and you can Download for use.
You can also set parameters for invoices to be automatically generated:
This way the system will email you invoices automatically, using the criteria you specify: