There are a few steps that can help you to get crispy air fryer tater tots. First, don't overcrowd the air fryer. If you can fit all the tots in a single layer they will have the best chance of getting crispy. Second, if you do need to cook more than just a single layer, add more time to the air fryer and give the tater tots a shake and a mix every 5 minutes or so to make sure they are evenly browning. Last, you can also spray a little oil on the tater tots to help them get crispy.