Preheat your air fryer to 400°F to ensure it is hot enough to create a crisp exterior.
Slice the russet potato into thin, uniform wedges and pat them thoroughly dry with a paper towel to remove excess starch.
In a small bowl, toss the potato wedges with the avocado oil and half of the sea salt, black pepper, and garlic powder.
Place the potatoes in the air fryer basket in a single layer and cook for 10 minutes, shaking the basket halfway through.
While the potatoes cook, whisk together the all-purpose flour, light beer, paprika, and the remaining sea salt, black pepper, and garlic powder until a smooth batter forms.
Pat the cod fillets dry with a paper towel, then dip each piece into the beer batter, allowing any excess to drip off.
Move the potatoes to one side of the air fryer basket and place the battered fish on the other side, or cook the fish in a second batch if space is limited.
Air fry the fish and chips together for an additional 8 to 10 minutes, flipping the fish halfway through, until the batter is golden brown and the fish flakes easily with a fork.
Serve immediately while the batter is hot and the potatoes are at their peak crispness.