To cook frozen fish sticks in an air fryer, preheat the air fryer to 400°F (200°C). Arrange the fish sticks in a single layer and optionally spray with a light coating of cooking oil. Cook for 8-10 minutes, flipping halfway through, until they are golden brown and crispy. Enjoy your air-fried fish sticks with your favorite dipping sauces or in a variety of dishes like tacos or salads.