Multi image gallery on product page

Hi. I’m struggling with creating a multi image gallery for my product display page (a fairly common layout, I would have thought). I have a large main photo. I’ve then inserted a collection list under that and connected that to pull multiple image from my Product database. It looks great as I have the large image and then 4 thumbnails underneath, but I want the main image to change when I click a thumbnail. I’ve studied the tutorial on “Multi-image field overview” but (unlike most Webflow tutorials) I find this one to be poorly explained (as it the accompanying video). I’m not sure whether I should be using a lightbox or something else and cannot find many resources for this issue. Any help appreciated.

Here is my site Read-Only: LINK
(how to share your site Read-Only link)