In a small bowl, combine the ground flaxseed and water. Stir well and let sit for 5 minutes to thicken, forming a flax egg.
Place the grated potatoes and grated onion in a clean kitchen towel or cheesecloth. Squeeze out as much excess moisture as possible.
In a large mixing bowl, combine the drained potatoes and onion with the chickpea flour, flax egg, salt, black pepper, and baking powder. Mix well until the mixture holds together.
Preheat the air fryer to 375°F (190°C) for 3 minutes.
Form the potato mixture into 8 equal-sized patties, about 3 inches in diameter and 1/2 inch thick.
Place the latkes in a single layer in the air fryer basket, making sure they do not overlap. You may need to cook them in batches.
Air fry the latkes at 375°F (190°C) for 10 minutes. Then carefully flip each latke and cook for an additional 10 minutes until golden brown and crispy.
Remove the latkes from the air fryer and let them cool slightly on a wire rack before serving.