Place pork roast, chicken broth and bbq sauce in instant pot.
Sprinkle the top of the pork roast with 1 - 2 tbsp of the rib rub seasoning
Place the lid on the instant pot and seal. Cook on high for 60 minutes and allow to depressurize naturally for 15 - 20 minutes before depressurizing the rest of the way and opening.
Shred the pork in the Instant Pot and allow it to absorb some of the cooking liquid. Add additional BBQ Sauce if desired.