Hi,
If I understand correctly, you need to add cover arts for ripped tracks ? In this case the easiest is to select all the tracks of the album and right click -> Cover Art -> Get from Internet.
This will launch a search window where you will be able to chose the one you want. If several albums are selected, several "search lines" will appear, allowing to chose the best picture for each.
Note that there are a lot of options for adding, storing, updating cover arts. You will find more details on the wiki page :
https://wiki.jriver.com/index.php/Cover_ArtEdit: another post from a week ago states that there have been some issues lately :
https://yabb.jriver.com/interact/index.php/topic,117234.0.htmlLookup of art cover works for me right now.