Preheat your air fryer to 400°F (200°C).
Slice the russet potato into thin wedges and toss them in a bowl with avocado oil and half of the sea salt and black pepper.
Place the potato wedges in the air fryer basket in a single layer and cook for 15 minutes, shaking halfway through.
While the potatoes cook, whisk the egg white in a small bowl until frothy, then gently stir in the beer, whole wheat flour, garlic powder, and paprika to create a smooth batter.
Pat the cod fillets dry with paper towels and season both sides with the remaining salt and pepper.
Dip each piece of cod into the batter, allowing any excess to drip off before placing them into the air fryer basket next to the potatoes.
Continue air frying the fish and chips together for another 8 to 10 minutes until the fish is opaque and the batter is golden brown.
Garnish with freshly chopped parsley and serve immediately with a fresh lemon wedge.