Which vitex do I buy for fertility

Trace • I have a 18 y.o. Boy. 14 y.o. Girl. Ttc since 2015. Miscarried Mar 2016/May 2018/Oct 2019/Apr 2020/Apr 2021/Nov 2021/Aug 2022/Dec 2022/May 2023. Ttc our 🌈 baby.

I wanna give it a try. I’m in Ontario Canada. Where do I buy it? How do I take it? Thanks ladies