Preheat air fryer, if needed. Even though my air fryer doesn't require it, I like to preheat for about 3-4 minutes for this
Place frozen salmon fillet in air fryer. Cook at 390 degrees for 5-7 minutes.
Brush salmon with olive oil and sprinkle on seasoning. Bake for an additional 5-7minutes to desired doneness. I don't bother turning the salmon over. I think it cooks fine without turning. Total time will be based on the thickness of your fillets and how your air fryer cooks. I recommend checking temperature after about 5 minutes.
Notes
You can try other ways to season the salmon also. A mustard sauce, pesto, and teriyaki sauce would all be good. If using sauce I'd cook a bit longer in the first step and more like 4-5 minutes in the second step to avoid burning the sauce.All air fryers cook slightly differently so you'll want to tweak the time on this recipe as needed for your model. You'll also find that different types of salmon take different cooking times as well. Air fryer is really just trial and error, just be sure to make notes on how long yours takes. I like to keep a Google doc with all the different air fryer cooking times/temps but use whatever method works best for you.