In a small bowl, combine the olive oil, salt, paprika, pepper, herbes de Provence, and cayenne.
Place the chicken on a cutting board, then rub the olive oil and spice mixture under the skin and all over the outside.
Stuff the cavity with the lemon halves, garlic cloves, and 3 or 4 wedges of onion.
Pour the broth into the electric pressure cooker and add the remaining onion wedges, carrots, and celery. Insert a wire rack or trivet on top of the vegetables.
Place the chicken, breast-side-up, on the rack.
Close and lock the lid of the pressure cooker, making sure that the valve to “Sealing.”
Cook on high pressure for 6 minutes per pound (21 minutes for a 3 1/2-pound chicken).
When the cooking is complete, hit Cancel and allow the pressure to release naturally for 15 minutes.
After 15 minutes, turn the valve to “Venting” to quick-release any remaining pressure.
Once the pin drops, unlock and remove the lid.
Carefully remove the chicken to a clean cutting board. Remove the skin and cut the chicken as desired.