Hello, Nick,
In order to make it on the production site, first of all, navigate to the Dashboard >> XSTORE >> Theme Options >> Theme Custom CSS >> Global and then add the code you see in this image: https://postimg.cc/BP6Wpv68 after that navigate to the Dashboard >> YITH >> Wishlist and set same settings that I set on this site: https://www.staging22.esthe.co.uk and then check back to your site after clearing the browser cache.
Regards 8Themes Team.