Board Thread:Support Requests - Designing Your Wiki/@comment-36535642-20191225093133/@comment-9605025-20191225201826

Here is what you need to do:
 * 1) and request for custom JS to be enabled on your wiki.
 * 2) Wait until custom JS has been enabled on your wiki.
 * 3) Add the following to either MediaWiki:Wikia.js or MediaWiki:Common.js (but not both).
 * Be sure to replace  with the actual URL of the image, not the file page. You can find the image URL by using Special:Filepath.

I also noticed that your MediaWiki:ImportJS has. Is that something you are in the process of adding? Right now, that page doesn't exist.