Adding a preloader

Hi guys, would really appreciate some help regarding the following;
Im trying to add a Custom Preloader to my site, based on this tutorial;

Its works fine, only problem is that in my Dev mode I don’t have the option between adding the code into my site or page code panel, which leaves me (when adding it to the homepage) with a loader that shows every time going back to the homepage, and not as I would like it to, only when loading the hole site. I tried instead adding the code to the masterpage.js, cause its the only other option, but leaves me with same result. Anyone that knows where I find the site code panel in the dev mode? As in the video above it should like like this:

but in my dev mode it looks like this:

I tried contacting Wix support, but they didn’t know how to fix it…

Stay safe, best regard
Malene

Hey Malene, did you find a solution? I’m running into the same issue