Prep the salmon: Pat the fillets dry with paper towels. This helps them brown and prevents steaming.
Season: Brush both sides with olive oil. Sprinkle with 3/4 teaspoon salt, black pepper, smoked paprika, and garlic powder. If using skin-on fillets, season the flesh side a bit more than the skin side.
Preheat the air fryer: Set it to 390°F (200°C) for 3 minutes. A hot basket helps the surface turn golden.
Arrange in the basket: Place salmon in a single layer, skin-side down if using skin-on. Leave a little space between fillets for airflow.
Cook: Air fry for 7–10 minutes, depending on thickness. A 1-inch-thick fillet usually takes about 9 minutes. The salmon is done when it flakes easily and reaches 125–130°F for medium (or up to 140°F if you prefer more done).
Make the lemon butter: While the salmon cooks, melt the butter in a small saucepan over low heat. Add minced garlic and cook 30–45 seconds until fragrant, not browned. Stir in lemon zest, 1 tablespoon lemon juice (more to taste), the remaining 1/4 teaspoon salt, and parsley. Remove from heat.
Finish: Transfer salmon to plates, spoon lemon butter over the top, and add extra lemon wedges on the side.
Serve: Pair with rice, roasted potatoes, a simple salad, or steamed veggies. The sauce is great drizzled over sides too.