Generously salt and pepper the chicken. Place the oil in the Instant Pot, set to hot sauté, and brown chicken in 2 batches. (about 7 minutes)
Place all the chicken in the instant Pot and add the soy sauce, sugar, vinegar, garlic, bay leaves, yellow onion, and ½ teaspoon pepper.
Attach lid, close vent, and pressure cook on high for 8 minutes. Carefully fast release pressure and remove the lid when Instant pot is ready being careful not to get burned. Turn Instant Pot back to high sauté setting, bring mixture to a boil, and continue cooking until sauce is dark brown and fragrant.