In a small saucepan, whisk together ½ cup water, coconut aminos, honey, rice vinegar, ginger, and garlic. Bring to a low simmer over medium heat, stirring occasionally.
Meanwhile, whisk together the remaining water (2 tablespoons) with the tapioca starch. This is your slurry which will thicken your sauce. Set aside.
After the sauce begins to simmer, turn heat to low and add in the slurry. Continue to cook, stirring constantly, until the sauce is thick enough that it coats a spoon (this should only take 30 seconds to a minute).
If desired, reserve ¼ cup of sauce to brush on the chicken after frying. Then, place chicken pieces in a large mixing bowl and pour remaining sauce over chicken. Stir chicken and teriyaki so that all pieces are fully coated.
Using a tongs, place chicken pieces in bottom of your air fryer basket. It's okay if pieces are touching, but try not to overlap pieces.
Set timer for 13 minutes and cook at 380 degrees F (if your air fryer requires pre-heating, make sure it was preheated). Stir chicken, or shake basket half way through cooking time.
Cut one of your largest pieces of chicken in half to ensure it's cooked through. If needed, continue cooking in 1-2 minute intervals.
If you saved some teriyaki, brush chicken pieces with additional sauce before serving. Enjoy!