Preheat the air fryer to 400°F for about 3 minutes.
Stir together olive oil, lemon juice, garlic powder, paprika, brown sugar, salt, and pepper to form a paste.
Pat salmon dry. Rub the paste all over the fillets, coating evenly.
Arrange salmon skin-side down in the basket, leaving space between pieces.
Air fry until the salmon flakes and reaches 125–130°F in the thickest part, 8–10 minutes.
Rest 2 minutes. Sprinkle with parsley and add a squeeze of lemon if you like.