Preheat the air fryer to 400°F (200°C) for 5 minutes.
In a large bowl, combine the shrimp, olive oil, chili powder, ground cumin, smoked paprika, garlic powder, onion powder, salt, and black pepper. Toss until the shrimp are evenly coated with the seasoning.
Add the sliced bell peppers and onion to the bowl with the shrimp and toss again to combine.
Place the shrimp and vegetable mixture in the air fryer basket in a single layer. You may need to cook in batches depending on the size of your air fryer.
Cook for 8 to 10 minutes, shaking the basket halfway through, until the shrimp are opaque and cooked through and the vegetables are tender-crisp.
While the shrimp and vegetables cook, warm the flour tortillas in a dry skillet over medium heat for about 30 seconds per side or wrap them in foil and warm them in the oven at 350°F (175°C) for 5 minutes.
Remove the shrimp and vegetables from the air fryer and transfer to a serving dish.
To assemble the fajitas, place a portion of shrimp and vegetables on each warm tortilla.
Top with shredded cheddar cheese, a dollop of sour cream, salsa, and chopped fresh cilantro.
Serve immediately with lime wedges on the side for squeezing over the fajitas.