Hi,
Then, you can customize the "order notification" email via the menu System>Emails. It is sent when you click on the "email" button of the order details page.
If you want to send an email on top of the order status email which is already sent with the link to the downloadable files of the products, there is no automatic system for that directly in HikaShop.
You would have to install AcyMailing on your website and create a filter to automatically send an AcyMailing email when the order is confirmed.