Background Script not working

Hello Developer Community, I am trying to use background scripts to show flag messages on issue and encountered this problem:

On my network tab, the files load successfully. However, the script does not trigger. I think it’s because of the iframe timed out. I’d like to ask for help on how to use the background script properly.

I’m currently just trying to log messages and it doesn’t show.
I saw on the other topic/docs that all.js is needed but even if I add it, it doesn’t work.
Here is the code on the file: (This is a .vm file)

Also, here is the background script call on atlassian-connect.json: