Where do I enter Site Code

Question:
A project I’m working on calls for entering a script in the site code so that it will run on all pages in the header. However, the AI I’m using to help me with the code has outdated navigation information for wix editor and I can’t find how to get to the site code.

This should help

this doesn’t actually help because I’m trying to run a script in Velo. This is for embedding.

I found the solution by accident. It’s apparently not called site code as I was led to believe. It’s the master page. When I selected my element in the header to rename it, a button appeared underneath to open the master page.js

@Michael_Freed yes, that is correct for velo, but you can also do through custom code in the site settings as linked above.