Board Thread:Support Requests - Getting Technical/@comment-39451797-20200805235930

I've been trying out the 'Template:USERNAME', but each time it only displays "". So I've been browsing Wiki forums and I found one archived. It says that you have to add the following code to "MediaWiki:Common.js" (Of which I copied and pasted from the Forum) to enable it to work: /* Username replace feature * Inserts viewing user's name into * Put text inside the spans to be viewed by logged out users * Originally by Splarka, then by Spang, * This (jQuery) version by wikia:User:Joeyaa, written to be backwards compatible */ if (wgUserName != 'null') { $('.insertusername').html(wgUserName); } Unfortunately, it said that "Custom JavaScript" is disabled on the Wiki I'm working on. I'm confused what to do next. Could someone please confirm if this is correct, and if so, what should I do next? 