Fancybox in product image not working with theme's product.js

[cobertec]

Hi, everyone this is my first thread, I'm a newbie in prestashop, I recently received a prestahop website to mantain. 

The client ask for product pictures to be open through fancybox, but is not working. I've been looking a lot of threads with no luck, the one thing it works is to replace product.js of the default prestahop theme to the client product.js theme. 

Could anyone help, which line do I need to modify..

Thank you.

I attach both files if is it helpfull.

PS version. 1.6.0.13
Theme: Modez

Shop URL: https://campomar.com.es (It has a javascript on console, but is because of Google Analytics module, I have deactivate it and fancybox keep failing.

product-modez-theme.js product-default-theme.js

Edited June 23, 2020 by cobertec
add shop url (see edit history)