Trim your asparagus. (See notes.) Toss with olive oil and liberally season with salt and freshly cracked pepper. Add to basket of air fryer and cook at 400º F for 7-11 minutes, depending on how large the spears are.
Remove basket after 5 minutes and gently shake. Keep an eye on the asparagus for the rest of the cooking time. The asparagus is done when vibrantly green with the ends beginning to brown. Remove from air fryer immediately as soon as it's done.