After enabling the PDF invoice plugin, you will get:
1.A Reports tab in back-end, through which administrators get the facility to generate either one or bulk invoices at a time. Invoices are generated for either in between the given dates or for the given invoice key.
2.A Download Invoice button in front end on invoice page, through which customers can download one of his/her invoice at a time.
3.A plugin parameter where the limit of invoices for bulk downloads can be set. It applies for the back-end only. It should be set as per the server capacity. (Recommended limit is 50)