Preheat the air fryer to 400°F.
Slice the russet potato into thin wedges and toss them in a bowl with half of the avocado oil, sea salt, and paprika.
Arrange the potato wedges in a single layer in the air fryer basket and cook for 15-18 minutes until the edges are crisp and golden.
While the potatoes cook, whisk together the whole wheat flour, light beer, garlic powder, and black pepper in a shallow bowl to create a smooth batter.
Pat the cod fillets dry with a paper towel and dip each piece into the beer batter, ensuring they are fully coated.
Remove the potatoes from the air fryer and set aside. Lightly spray the basket with the remaining avocado oil.
Place the battered fish in the basket and air fry at 375°F for 8-10 minutes, flipping halfway through, until the crust is bubbly and the fish flakes easily with a fork.
Serve the hot fish alongside the potato wedges immediately.