Preheat your air fryer to 400°F (200°C) to ensure a high-heat environment for crisping.
Scrub the russet potato thoroughly and cut it into even wedges.
In a bowl, toss the potato wedges with avocado oil, paprika, and a pinch of sea salt until coated.
Place the wedges in the air fryer basket in a single layer and cook for 15 minutes, shaking the basket halfway through.
While potatoes cook, whisk together the flour, light beer, garlic powder, and black pepper in a shallow bowl until the batter is smooth and thick.
Pat the cod fillets extremely dry with paper towels; this is a Bobby Parrish pro-tip to ensure the batter adheres properly.
Dip each cod fillet into the beer batter, allowing any excess to drip off, and place them into the air fryer basket next to the potatoes.
Air fry everything for another 10-12 minutes until the fish is opaque and the coating is golden and crunchy.
Serve the fish and chips immediately with a fresh lemon slice for a bright, acidic finish.