Remove all parts from the chicken cavity (usually in a bag); rinse and pat dry with a paper towel.
Salt the cavity with half of the salt and pepper. Place onion and lemon in the cavity of the chicken. Using kitchen twine, tie the legs of the chicken.
Mix the remaining salt and pepper, paprika, garlic powder and onion powder together to create a spice rub. Coat half of mixture on the breast side of the chicken. Flip and season the other half of the whole chicken with the spice rub.
Turn the Instant Pot to the SAUTÉ setting. Add 1 tbsp oil. Place the chicken, breast side down, in the preheated Instant Pot.
Allow the breast side to crisp up, 4-5 minutes. Carefully flip the chicken over to the other side, 4-5 more minutes.
Add the trivet your electric pressure cooker came with, and place whole chicken over trivet, breast side up. Add in the chicken stock, or water.
Place the lid on and make sure the vent is in the sealed position. Set to manual HIGH pressure for 25 minutes. Once done, allow the Instant Pot to depressurize naturally, about 10-12 minutes. Release any remaining pressure using a wooden spoon.
Remove from Instant Pot. Transfer the chicken to a serving dish, or cutting board. Let the chicken rest for about 10 minutes before carving. Make sure to remove kitchen twine, onion and lemon from cavity before carving.