Board Thread:Support Requests - Getting Started/@comment-47155478-20201020161903/@comment-31208684-20201020165901

You go to the page Special:WikiFeatures in the wiki you're trying to enable it in, but if your wiki is a UCP Wiki, you won't be able to enable it. If you're asking how you find it, on wikis it's still enabled in, you can go directly to the link Special:Chat.

Find out more at Help:Chat.