While you can use fresh or frozen Tilapia for this recipe, I recommend that you first allow any frozen filets to thaw in the refrigerator before adding them to the preheated air fryer.    If you go ahead and cook the filets from frozen, you run the risk of the fish not being cooked through completely. While you could add extra cooking time, you could end up drying out certain parts of the filets while the center remains undercooked.