Preheat the air fryer to 370°F (185C) for 5 minutes.
Make the sandwich:
Place the sliced bread on a flat surface and butter both slices of bread. Flip the bread slices over, place the cheese, and close the sandwich, buttered sides out.
Take a toothpick and slide it through the middle of the sandwich to keep it together inside the air fryer.
Air Fry:
Place the cheese sandwich in the preheated air fryer. If making more than one grilled cheese at a time, make sure not to stack them.
Air fry it for 2 minutes on the first side, open the air fryer and flip the sandwich over. Air fry the second side for another 2 to 3 minutes.
Serve:
Remove the toothpick and serve the grilled cheese sandwich.