Show images from featured instead of gallery tab

Hi,

I have a theme that shows images (in home, archive, category…) only from gallery tab
(so i can’t re-use an image to other posts). As you know an image can only get attached to 1 post. I found a plugin that you can attach an image to more posts, but it doesn’t work for this theme.

Does anybody know how to change the code so to use Featured images instead?

thanks 😉