I have the Comicbase 2020 archive edition and installed the software. When I go into any comic book series, the option of downloading covers is greyed out. Is there some setting I have mess with in order for that to work?
Yes. Use the View drop-down box and select Include Value Graph.
A couple of items.
If you drag the 'splitter' bar ' (the line between the Grid data on the bottom and the top information) up too far, the Value Graph will be 'turned off' as it needs a minimum amount of space to display. Some people with small laptop screens prefer to not display the Value Graph in exchange for a few more lines of Grid data being show. You can drag the splitter bar down and redisplay the Value Graph if you go too far up.
Even with the Value Graph displayed, you have to select an issue for it to be shown. For example, going to a Title will not show the Value Graph. Selecting an Issue will display it.