Take the giblet bag out of the chicken and wash with cool water and pat dry.
Stuff the carcass with carrot, celery, lemon and onion. Rub the chicken with olive oil, Italian Seasoning and salt and pepper.
Fill the Instant Pot with water to the base of the silver steam rack or 2 inches if you don’t have the rack.
Place chicken on steam rack and set the Instant Pot for 25 minutes. Note: Set for 15 minutes if you are adding potatoes and vegetables. When the time is up release pressure valve on the top of the lid and wait till the small silver ball drops, this means the pressure is low enough to open the lid. Note: If adding potatoes and vegetables add them quickly so you don’t loose a ton of heat. Close the lid and set the Instant Pot for 6 minutes. It will take a few minutes to gain pressure so it may take closer to 15 minutes for the timer to go off. Release the steam valve and wait for the silver ball to drop. I use small red potatoes and do not chop them but if you have large potatoes cube into large pieces.
The chicken is fully cooked now but if you like the skin a little crispy transfer it to a baking sheet and broil on high for a 3-5 minutes.