Leviticus 5:7-8

⁷If you are poor and cannot afford to bring a lamb, you must bring to Yahweh two doves or two young pigeons. One will be an offering for your sin and one will be an offering that will be completely burned on the altar.

⁸You must bring them to the priest. First he will offer one of them to be an offering for your sin. He will wring/twist its neck to kill it, but he must not pull off its head completely.