Leviticus 4:19-21

Then the priest must remove all the animal’s fat and burn it on the altar, just as he does with the bull offered as a sin offering for the high priest. Through this process, the priest will purify the people, making them right with the LORD, and they will be forgiven. Then the priest must take what is left of the bull and carry it outside the camp and burn it there, just as is done with the sin offering for the high priest. This offering is for the sin of the entire congregation of Israel.