Instant Pot Chicken Adobo and Rice

Name: Instant Pot Chicken Adobo and Rice
Ingredients: 3 to 3 1/2 pounds bone-in, skin-on chicken legs and thighs (or 1 1/2 to 2 pounds boneless skinless chicken thighs); 1 medium yellow onion , sliced; 4 cloves garlic , chopped; 1/3 cup soy sauce (use low sodium soy sauce for less salt, or tamari for gluten-free); 3 tablespoons white vinegar (or rice vinegar for a milder flavor); 1 tablespoon brown sugar; 1 teaspoon black peppercorns; 3 dried bay leaves; 1 1/2 cups long-grain white rice; 1 1/2 cups water; Thinly sliced green onions , to garnish the rice (optional)