Preheat the air fryer to 375°F (190°C).
In a large bowl, toss the apple strips with lemon juice to prevent browning.
In a separate bowl, mix together the cinnamon and sugar.
Place the flour in a shallow dish, the beaten egg in another shallow dish, and the panko breadcrumbs in a third shallow dish.
Coat each apple strip first in flour, then dip it into the beaten egg, and finally coat it with panko breadcrumbs.
Arrange the coated apple fries in a single layer in the air fryer basket. Spray lightly with cooking spray.
Air fry for 10-12 minutes, shaking the basket halfway through, until the apple fries are golden brown and crispy.
Remove from the air fryer and sprinkle with the cinnamon-sugar mixture while still warm.