How do I show or hide Tot at will with a hotkey on macOS?

1. Go to Settings > Control
2. Tap the Record Shortcut button to Record a Hotkey, for example enter Function 14 on the keyboard as a new Hotkey entry for Tot

Now Tot will appear and hide itself whenever you press the F14 key. If there is a hotkey conflict with another app, you will get a warning to avoid recording that particular keystroke

There is also an option to have Tot window show or hide directly beneath the mouse pointer:

Settings > Behavior > Window hotkey follows mouse

Now when you use the hotkey to show/hide Tot, it will always appear directly beneath your mouse cursor which can be very handy for quickly coping and pasting text.