You can make your own chicken seasoning using 1/4 teaspoon of the following: onion powder, paprika, black pepper, and sage. You can also simply use salt and pepper.
Soy sauce is used in this recipe to make the chicken moist and juicy and to add flavor.
I have not tested this recipe without using the grill rack.
Find it online: https://allguiderecipes.info/air-fryer-chicken-kebabs/