Sprinkle the rub all over the ribs, generously coating all of the sides.
Place the trivet (or rack) in the bottom of a 6-quart or larger Instant Pot. Pour in the water, apple cider vinegar, and liquid smoke. Place the ribs inside the pot, standing them on the trivet on their side and wrapping the rack around the inside of the pot like a circle.
Cover and seal the Instant Pot. For baby back ribs, Cook on high (manual) pressure for 23 minutes. Allow the pressure to release naturally for 5 minutes, then vent to release the remaining pressure. For country style/spare ribs: Cook on high for 35 minutes. Allow the pressure to naturally release completely (about 15 minutes).
Towards the end of the ribs’ cook time, place a rack in the upper third of your oven and set it to broil. Line a large baking sheet with aluminum foil. Transfer the cooked ribs to the foil, then brush liberally with barbecue sauce. Place under the broiler just until the sauce begins to caramelize, about 2 minutes.

Instant Pot BBQ Pork Ribs