display thumbnails with category list

I’d like to display thumbnails of the featured images I’ve added for each item in this category list. The list is being called in with a shortcode from another plugin, https://www.ads-software.com/plugins/list-categories/ which I’m guessing I’d have to hack to work this way. Or perhaps I could hack archive.php similar to the way I got the featured image to show on the single post page. https://quakertheology.org/category/issues/issue-1/

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