Whisk together the flour, baking powder, salt, and sugar in a large bowl.
Add the warm milk and 1 tablespoon of oil. Stir with a fork until a shaggy dough forms.
Turn the dough out onto a lightly floured surface and knead gently for 1 to 2 minutes, just until smooth. Do not overwork.
Cover the dough with a clean towel and let it rest for 10 minutes. Meanwhile, preheat the air fryer to 360°F (182°C).
Divide the dough into 8 equal pieces. Roll each into a ball, then flatten and stretch into a ¼-inch-thick disk about 5 to 6 inches across. Cut a small ½-inch slit in the center of each.
Lightly brush or spray both sides of each disk with oil.
Place 1 to 2 disks in the air fryer basket (do not overlap). Cook at 360°F for 5 minutes, flip, then cook another 3 to 4 minutes until golden, puffed, and crisp.
Repeat with the remaining dough. Serve warm with your choice of savory or sweet toppings.