Alt + Tab isn't in the list of Key Combinations, and also only counts Alt

I only just downloaded WhatPulse earlier today, so its possible I’m just missing something obvious. But, I don’t see Alt + Tab in the list of Key Combinations. I also noticed that Alt + Tab only counts Alt as a keystroke, even if I hold Alt and press tab multiple times. Is there any way for me to add it to the list of Key Combinations at the very least?