I'm not sure what code you're talking about, but most of the answers are referring to the chances.txt file, which is first accessed via the advanced tab (which you can only see in Full view). Find the "Apply modifications to USFM...." line, ensure that the tick-box has a tick, and click on 'edit'.
Once you've opened the file, then it becomes available on the "view + edit" tab.
I'd add a picture or 2, but that seems impossible at the moment.