Spray the basket of the air fryer with some vegetable oil.
Preheat the air fryer for 5 minutes at 375°F (190°C).
Place the hamburger meat in the air fryer basket for 8 minutes, flipping the meat every 4 minutes or so. (Don't overcrowd the basket, lay the burgers in a single layer).
Open the air fryer to see if they are cooked enough for you, and heat them for a couple more minutes if you wish.
Serve while warm.
Notes
* If using frozen hamburgers, cook them for about 4-5 more minutes.