just about to ask the same thing, instinctively typed el exterior, and then saw that they recommended la afuera....
My Oxford dictionary says that afuera and fuera are interchangeable. In European Spanish, fuera is the preference.
que rayos...the app literally suggests afuera and doesn't give exterior as a translation until you get it wrong
La FUERA, always ask for that when i go to my local favourite Spanish restaurant, never been seated inside yet