Ideal way to cook a chicken To get a marinated chicken to be golden brown on the outside, maybe a bit crispy, and tender on the inside, which is a better approach:


Cook it on high heat until it browns, then cover it and cook it on very low heat until done
Cover it and cook it for a couple of hours on low heat, then uncover it and blast it on high until it browns
Other


In the past I've cooked it on low heat, circa 190 celsius, for three hours, uncovered. It's tender and juicy, but it doesn't crisp.
You make no mention of basting. 190 is more than high enough though 3 hours sounds a bit long. Basting fat over the skin throughout cooking is the key to crispy skin. Covering it is a sure way to soggy skin.