Ghost Side-by-Side Editor

Version: 3.15.1

I just upgraded from a ye olde version and I was wondering — how do I get the side-by-side (split) view back for Markdown editing? I understand that if I want to continue using Markdown for all editing, I now have to use a single Markdown card as the post; however, I couldn’t find a way to reenable the side-by-side editor.

I found Ghost Split Editor Preview from a couple of years ago, but that doesn’t seem to work anymore, at least on Google Chrome (81.0.4044.129 (Official Build) (64-bit)) on MacOS Catalina (Version 10.15.3 (Build 19D76)). I tried substituting Command for Control (Ctrl) to see if that would make a difference (sometimes that’s necessary on MacOS), but it was to no avail.

How can I enable the side-by-side editor?