Make the compound butter by combining 1/2 cup softened unsalted butter, minced garlic, chopped rosemary, chopped thyme, lemon zest, salt, and pepper in a mixing bowl until evenly mixed.
Carefully loosen the skin over the breasts and legs with your fingers to create pockets, then spread most of the compound butter under the skin, distributing it over both breasts and legs.
Tie the chicken legs together with butcher's twine and tuck the wing tips under the bird if desired.
Pour 1 cup chicken broth into the pressure cooker pot and place the wire rack or trivet inside. Set the chicken on the rack, breast-side up.
Melt a small amount of the remaining compound butter and brush about half over the outside of the chicken.
Seal and cook on high pressure for 15 minutes, then allow a natural pressure release for 5 minutes before performing a quick release for any remaining pressure.
Remove the chicken from the cooker. Using the air crisp or air fryer function at 400°F (or an oven broiler), brush the chicken with the remaining butter and cook 10–15 minutes until the skin is browned and crisp.
Let the chicken rest a few minutes before carving and serving.
