Help with fancybox?

Help with fancybox?

I am still learning jquery, and I am trying to get fancybox to work on my website. I have been fighting with it for a few days and finally followed  https://www.granneman.com/webdev/coding/css/fancybox-a-better-lightbox to get it to work. It did, but only in the test folder. As soon as I moved all the files out of there and into my regular website folders, it stopped working. It opens the image URL in the tab rather than in a lightbox, and that's the problem I've been having from the start.

This is my test page, which is exactly the same as it was in the test folder, just renamed from index and moved to the main website:

What am I doing wrong?