Preheat your air fryer to 400°F (200°C).
Wash and cut the russet potato into thick wedges, then toss them in a bowl with the avocado oil and a pinch of sea salt.
Place the potato wedges in the air fryer basket and cook for 15-20 minutes, shaking halfway through, until they are tender and browned.
While the potatoes cook, whisk together the flour, light beer, egg white, garlic powder, and paprika in a shallow bowl until the batter is smooth.
Pat the cod fillets completely dry with a paper towel and season lightly with sea salt and black pepper.
Dip each cod fillet into the beer batter, allowing any excess to drip off so the coating remains light.
Carefully place the battered fish in the air fryer basket (use a parchment liner or lightly grease to prevent sticking) and cook at 375°F for 10-12 minutes until the exterior is crunchy and the fish flakes easily.
Serve the hot beer-battered cod immediately with the crispy potato chips.