Gallery images not clickable

I really like this plugin except for that the images displayed in a gallery are not clickable. What I need to do is to assign a link to each image so that when you click on it, it will go to a page of my choice. Basically, I want the “see more” button link to be applied to the image itself. It doesn’t look like there is a way to do this with the premium version. Is there a way to modify the source code to get this much needed functionality?

https://wordpress.org/plugins/portfolio-gallery/