How do you whiten your bebe area - specifically on the sides , your underarms & the bottom of your butt? Please I need your help.

I also need some help with these kind of problem. Please help us. . Thanks. Bcoz since I gave birth, until now (8months had passed) I still have these dark spots. (underarm, groin, and butt area, even on stomach) I'm still breastfeeding now. And I've read that while breastfeeding, I can't still use whitening products. Maybe I'll use it afterwards. Anyway, I still need help. Thanks.