Preheat your air fryer to 375°F (190°C). In a shallow bowl, combine 1/2 cup all-purpose flour, 1/2 teaspoon paprika, 1/2 teaspoon garlic powder, 1/4 teaspoon salt, 1/4 teaspoon black pepper, 1/2 teaspoon onion powder, and 1/2 teaspoon baking powder. Dip the 2 boneless, skinless chicken breasts into the 1 large egg, and 1/4 cup buttermilk then coat them in the seasoned flour mixture. Lightly spray the chicken with cooking spray and place it in the air fryer basket in a single layer. Air fry for 10-12 minutes at 375°F (190°C), flipping halfway through, until golden brown and the internal temperature reaches 165°F (74°C). Let the chicken rest for a few minutes, then slice into strips.
In a small bowl, whisk together 1/4 cup ranch dressing, 1 tablespoon lemon juice, 1 tablespoon Dijon mustard, and 1/2 teaspoon garlic powder.
Lay the 4 large flour tortillas flat and spread a spoonful of the dressing on each. Add a layer of 1 cup lettuce, 1/2 cup carrots, 1/4 cup cucumber (if using), 1/4 cup tomatoes (if using), and 1/2 cup cheddar cheese. Place the sliced crispy chicken on top.
Fold in the sides of the tortilla and roll tightly to form a wrap. Slice in half and serve with extra dressing on the side.