This is very messy in an application like this. Making an image "clickable" doesn't involve some sort of transformation of the image itself. What's needed is to surround the image with an HTML anchor. Thumbnails, for example, look like this in the page code:
<a href="slides/mydog.html"><img src="thumbs/mydog.jpg"></a>
So, when you click on the the
mydog.jpg thumbnail it takes you to the
mydog.html page.
So why can't you do that with the slide images? In most skins, the slide images are shown in a lightbox, where the lightbox script itself is "listening" for clicks that will tell it what to do next: go to the next image, zoom in on this image, etc. The same is true when the slide image is shown on its own page - the slide image is surrounded by anchors and overlays that function as navigation instructions. There's no way to add even
more functions for clicking.
Usually, the best you can do is to bury your links in the caption for the image. For example, you might enter the
title or
comment as:
This is Köln. <a href="https://kolntour.com">Click here</a> for the city tour.