Preheat the air fryer to 400°F for 3-5 minutes.
In a small bowl, mix cajun seasoning, smoked paprika, garlic powder, dried oregano, onion powder, salt, black pepper, cayenne (if using), and lemon zest.
Pat your salmon dry with a paper towel. Then drizzle oil over the salmon.
Rub the seasoning blend evenly over the surface of the salmon, pressing gently so it adheres.
Place salmon skin side down in the air fryer basket, and top with lemon slices if desired.
Air fry at 400°F for 7-9 minutes, checking at the 7-minute mark, until salmon flakes easily with a fork or reaches an internal temperature of 145°F. Add 1-2 minutes for thicker fillets.
Remove salmon from the air fryer and immediately squeeze fresh lemon juice over the top.
Garnish with finely chopped parsley (or cilantro) and extra lemon slices, then serve.
If cooking the vegetables, air fry on 400F for 10-12 minutes, shaking halfway.