In an air fryer safe bowl, combine 1/2 cup oats with 1/2-3/4 cup of milk, and 1- 1 1/2 tsp lemon juice (depending on the size of your bowl, you want to make sure the oats are slightly covered by milk). Let sit for 10 minutes.
Layer on top of the oatmeal lemon zest, blueberries, and a sprinkle of brown sugar.