Place the trivet in an instant pot and pour ¾ cup of water in it.
Place chicken drumsticks on the trivet and close the lid tightly. Close the vent.
Press poultry function and let it cook for 20 minutes.
Release the pressure naturally.
Take out the chicken drumsticks and evenly coat them with BBQ rub.
Put the drumsticks on cookie sheet lined with parchment paper.
Broil the drumsticks in preheated oven for about 2 min until the skin becomes brown from all sides. Serve.