Clean and prepare chicken. Rub chicken lightly with oil then rub inside and out with salt, pepper and spices. Set aside. Open beer can and drink (or pour out) 1/4 of the beer. Place beer can on a solid surface and open top of can with can opener. Fill can with garlic cloves, onions and peppers. Place the chicken on top of the can, making sure the beer can is nestled in the cavity of the chicken. Place can in holder (if using). Transfer the beer can chicken to your grill and place in the center of the grate, balancing the bird on its 2 legs to make it stable. Cook the chicken over medium-high, indirect heat with the grill cover on, for approximately 1 1/4 hours until the thigh juice runs clear when stabbed with a sharp knife. Remove from grill and let rest for 10 minutes before carving.