Can't give the Play button a shortcut in Harmony 20 Advanced

In Storyboard Pro (and Flash CS6, formerly), I like to map the “Play” button to the “Enter/Return” key, so I can quickly check an animation. I’d like to do that in Harmony 20 as well, but when I open Keyboard Shortcuts, I can’t find “Play” anywhere. Am I missing something, or is this a weird bug? If anyone has had and solved this problem, I’d greatly appreciate it.

Try - Toggle Playback - default: shift+return