Lay frozen chicken breasts out in one layer on plate, cutting board, or foil. Generously season tops of chicken breasts with poultry seasoning (or salt and pepper), gently rubbing seasoning onto chicken. Flip chicken breasts over and repeat seasoning process on other side.
Place trivet in Instant Pot. Pour chicken broth (or water) into pot, then place frozen chicken breasts on trivet. Stacking or overlapping chicken breasts on trivet is fine.
Secure lid on Instant Pot and set vent to Sealing position. Set Instant Pot to Manual High Pressure with 10-minute cook time (see Notes). Instant Pot will pressurize, then cook time will begin.
After cook time is up, Natural Release internal pressure 5 minutes, then Quick Release any remaining pressure. Carefully remove lid and set aside.
Check chicken breasts for doneness with internal meat thermometer. Internal temperature should read 160° to 162° Fahrenheit (see Notes). Remove chicken breasts from Instant Pot and set aside to rest 5 minutes.
After resting, shred, chop, or serve chicken as-is with desired sides. Alternately, use chicken for another recipe that calls for cooked chicken.