In a small saucepan, heat the olive oil over medium.
Add the onion and cook until softened. Then, add the garlic.
Cook the garlic until fragrant and add the tomato sauce.
Stir in the Italian seasoning and red pepper flakes, if desired.
Season with salt and pepper and remove from heat.
Begin assembling the flatbread by spreading sauce evenly on top.
Then, add the zucchini slices. Spread more sauce on top of the zucchini.
Sprinkle mozzarella cheese on top of the flatbread and carefully place back into the air fryer basket.
Cook at 375º for 3-5 minutes, or until cheese is melted and just beginning to brown.
Carefully remove from the air fryer basket and serve with fresh basil and Parmesan cheese, if desired.