ZSketch Functionality Missing?

While I bought ZBrushCore a year ago, I only recently began seriously using it (specifically, the 2018 version). I’ve been watching the tutorials of course, but when I attempted to learn how to use ZSpheres and ZSketch, I discovered that there is absolutely no ZSketch functionality in my program. Shift+A doesn’t activate Sketch mode, and there is no ZSketch subtool in my Tool palette. I can use ZSpheres to create mannequins, but that is about it. Otherwise, I’m forced to sculpt normally. Is there something I’m missing here? Was ZSketch removed? Is it part of ZBrush Pro instead? Here’s an example of my screen, if it helps.
Zbrush screen.PNG


Zbrush screen.PNG

ZSketch is not part of ZBrushCore. See the “Advanced Features” section towards the bottom of this page: