How to change the same artwork for multiple discs at once

Hi guys and girls

I have hundreds of added albums with Thai music in my ROON library (which was lost recently). I have now found the most of these albums, but the artwork is of course missing and ROON cannot find it bcs the names are something with Thai letters. I have before added the Thai national flag on them all.
How can I choose all these albums and add the Thai flag (Jpeg) to them all, instead of doing it manually one at a time which would take weeks.
Yes, I don´t mind that they have the same Thai as cover art, bcs I can see it from a distance that this is the Thai albums (I am married to a Thai woman, that´s why, and actually after hating these albums to start with, I now love them, and they are very relaxing to me)

best KK

It might work better to do that outside of Roon. Embed the artwork in the files or have them in each folder as folder.jpg.

Thanks James. How do I do that?

Best KnockKnock

There are many MP3 tagging tools (work with FLAC too) that will embed artwork. Foobar does; that is what I’ve used.