Show featured images in custom template

How do I show the featured image that I’ve attached to each download? I’m creating a custom template, but no one has been specific about the PHP script I need to actually show the featured image that I’ve attached to each download.

Here’s a screenshot of the images I’m referring to:
https://s6.postimg.org/xwd75ow1d/images.png

Any help would be greatly appreciated ??

https://www.ads-software.com/plugins/download-monitor/