Preheat your air fryer to 400°F to ensure it is hot and ready for the potatoes.
Cut the russet potato into thin, uniform wedges and toss them in a bowl with the avocado oil, paprika, and a pinch of sea salt.
Arrange the potato wedges in a single layer in the air fryer basket and cook for 15-20 minutes, shaking the basket halfway through until they are golden and crisp.
While the potatoes cook, prepare the batter by whisking together the flour, light beer, egg white, garlic powder, and black pepper in a shallow bowl until smooth.
Pat the cod fillets completely dry with a paper towel, then dip each piece into the batter, allowing any excess to drip off.
Once the potatoes are done, remove them and keep warm. Lightly grease the air fryer basket and place the battered fish inside.
Air fry the fish at 375°F for 10-12 minutes, carefully flipping halfway through, until the coating is crispy and the fish is opaque and flakes easily.
Serve the hot beer-battered fish immediately alongside the crispy potato wedges.