Grease the Air Fryer Basket with cooking spray and then slide inside.
Adjust the temperature of Air Fryer to 325 °F to preheat for 5 minutes.
In a bowl, add peppers, onion, oil, Italian seasoning, salt and black pepper and toss to coat well.
After preheating, arrange the bell pepper mixture into the greased Air Fryer Basket in a single layer.
Slide the basket into Air Fryer and set the time for 14-16 minutes.
After 3 minutes of cooking, flip the bell pepper mixture and arrange the brats on top.
After 8 minutes of cooking, flip the brats.
After cooking time is finished, remove the bell pepper mixture from Air Fryer and serve.