Preheat your air fryer to 390°F for 3 minutes. Don't skip the preheat, a cold basket means uneven cooking.
Snap the woody ends off the asparagus. Where it naturally snaps is exactly where it should break, no measuring needed.
Pat the spears dry with a paper towel. Moisture is the enemy of crispy. Dry them well.
Toss asparagus with olive oil, garlic powder, onion powder, Italian herbs, red pepper flakes, salt, pepper, and lemon zest in a large bowl until evenly coated.
Lay spears in a single layer in the air fryer basket, no overlapping, no stacking.
Air fry at 390°F for 5 minutes. Check at 4 minutes if your spears are thin.
Pull them out, hit immediately with a squeeze of fresh lemon juice, and serve hot.