Brush the bread slices lightly with oil or use oil spray.
Place them in the air fryer basket in a single layer.
Air fry at 170 degrees C / 340 degrees F for 2 to 3 minutes to lightly toast the bread.
Top each slice with chopped bell peppers, onion, corn, mozzarella, and cheddar.
Sprinkle oregano, salt, pepper, and red chilli flakes if using.
Air fry again at 170 degrees C / 340 degrees F for 3 to 5 minutes until the cheese melts and the edges are crisp.
Serve hot with ketchup or dipping sauce of your choice.