To do Alt + H + M on Mac in PowerPoint, download and install Accelerator Keys, then press Option, followed by H, then M.
Command: Convert to SmartArt Menu
This is how to do Alt + H + M on Mac in PowerPoint with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with PowerPoint.
Alt + H + M opens the Convert to SmartArt menu, displaying a gallery of SmartArt graphics you can use to transform your bulleted text into visual diagrams, process flows, hierarchies, and more.