To cook bratwurst in an air fryer, start by placing the raw sausages in the basket of the air fryer. Cook them at 350 degrees Fahrenheit for 8 minutes, then flip them over and cook for an additional 6 to 8 minutes. To ensure that they are fully cooked, use a meat thermometer to check that the internal temperature of the brats has reached 160 degrees Fahrenheit before removing them from the air fryer.