How do I configure a global hotkey for iTerm 2? I'm a new OSX user, and I've used Linux for the past 1.5 years, and I really can't live without dropdown terminal. So I googled, and came across this question: iTerm as a slide-out terminal from the top of the screen

However, it doesn't work for me. There's no option whatsoever like that, and there's no updated answers covering this. Is there a way to enable it, as google doesn't really help me with this.

I've included a picture of my keys tab here: 

It's not in the mappings menu either. I'm not married to iTerm, but TotalTerminal is discontinued. I did install Apptivate but it's not the same as a dropdown terminal.
You're in the wrong preferences. That's the Appearance settings, available with ⌘I or the Appearance tab in the app Preferences (⌘,). You should be in iTerm → Preferences (⌘,) to access the app preferences, then select Keys in the toolbar at the top.

Specifically: