Instant Pot Pork Shoulder

Name: Instant Pot Pork Shoulder
Ingredients: 1 medium yellow onion; 4 cloves garlic; 1 tablespoon packed light or dark brown sugar; 1 tablespoon chili powder; 1 tablespoon kosher salt, plus more as needed; 1/2 teaspoon ground cumin; 1/4 teaspoon ground cinnamon; 1 tablespoon olive or vegetable oil; 1 (4-1/2- to 5-pound) boneless or bone-in pork shoulder or pork butt; 1 cup low-sodium chicken broth or water; 1 1/2 to 2 cups tomato-based barbecue sauce (optional, if making pulled BBQ pork)