Heat a large skillet over medium high heat. Add the ground beef and cook, crumbling as it cooks, until the beef has browned, about 5 minutes. Drain any excess fat.
Stir in taco seasoning according to package directions.
Warm the tortillas and place them flat on a clean surface.
Add 1/4 cup of refried beans to the center of each tortilla. Add 1/2 cup of ground beef onto the top of the beans and spread it out in a large circle, the same size as the tostada shells. Place one tostada shell on top of the beef.
Spread some of the sour cream on the tostada. Sprinkle on the cheese, lettuce, and tomatoes.
Tightly fold the edges of the flour tortilla over the top of the stack, making pleats, until fully covered. Then flip the whole crunch wrap over to keep it secure.
Lightly spray both sides of the wrap with cooking oil. Set in the air fryer, seam-side down, and cook at 400°F (200°C) for 4 minutes. Flip the crunch wrap and cook for an additional 4 minutes.
You will likely need to cook them one at a time, depending on the size of your air fryer.
All air fryers have different wattage and may cook at different rates. You may need to adjust the time or temp for the best results.