Remove and discard neck and giblets if not already done. Rinse chicken inside and out; pat dry with paper towels.
Rub chicken with seasoning. When seasoning: Loosen the skin on the chicken breasts and thighs of the chicken by sliding your fingers between the skin and the meat. Massage the spice mixture on the skin, under the skin, and inside the cavity.
Place onion in the neck of the chicken.
Empty half the beer from the can and remove the very top of the can with kitchen shears. Sprinkle some of the seasoning in the beer and then place the chicken on the beer can.
Balance the chicken on its two legs and the can like a tripod and place in a baking dish and put into preheated oven. Cook for 20 minutes at 475F and then turn the over down to 425F and cook for another 45 minutes more or less based on the weight of the bird.