Press tofu for at least 15 minutes, using a heavy pan or a weighted-down baking sheet to squeeze the excess moisture from the tofu block.
Meanwhile, in a large bowl, combine the soy sauce, sesame oil, and garlic powder.
Cut the tofu into 1/2-inch cubes. Add the tofu pieces to the marinade bowl and let the mixture sit for 15 minutes.
Preheat the air fryer to 375 degrees Fahrenheit.
Add the tofu to the basket in a single layer and cook for 10 to 15 minutes, flipping the tofu halfway through or shaking the basket to ensure even cooking. You may have to cook the tofu in multiple batches, depending on the size of your air fryer.