In a small bowl, combine the smoked paprika, cumin, garlic powder, 1 teaspoon black pepper, 1 teaspoon salt, brown sugar, and cayenne.
In a large skillet set over medium-high heat, warm the oil. Season the chicken with the remaining salt and pepper and, if you have some kitchen string, tie the legs together. Sear the chicken in the skillet, turning it to brown all sides, 10 to 12 minutes total. (Alternately, if you’re using a pressure cooker and it has a sauté function, you can sear the chicken in the pressure cooker, leaving you with one less dish to clean.) Let the chicken cool enough to handle, about 3 minutes.
Place the steam rack inside of the pressure cooker. Pour in the chicken stock and beer. Rub the chicken with the spice rub and place it in the Instant Pot or pressure cooker on the steam rack. Secure the lid and cook under high pressure for 18 minutes. Allow to naturally release for 5 minutes, then quick release and remove the lid.
Remove the chicken and serve: Using tongs, carefully move the chicken from the Instant Pot or pressure cooker to a platter. Carve and serve immediately with hot sauce, if desired.