Board Thread:Support Requests - Designing Your Wiki/@comment-33688175-20200317170752/@comment-9605025-20200424031236

It isn't "showing" because the default color scheme camouflages it with the page background. If you try it with a non-default color scheme, then you will see it.

In general, copying tempaltes from Wikipedia is not recommended. In order starting with the most commonly applicable:
 * 1) They often involve a maze of nested transclusions and module invokations. All of these would need to be copied for the template to work properly.
 * 2) The versions of extensions (and even the core MediaWiki platform) can differ between Wikipedia and Fandom. This means that Wikipedia may be using a new function or option that is not available on Fandom. Sometimes this is due to Fandom using an older release and other times this is due to Fandom customizing the version it uses. For instance, Fandom has removed several "standard" functions from the Scribuntu extension. In case you don't know, the Scribuntu extension is what allows wikis to use Lua modules.
 * 3) Wikipedia uses some extensions that Fandom does not. If the template uses one of these extensions, then it won't work on Fandom.

You use Template:Documentation. You can inspect that template as an example of how to use it.