How is underarm pigmentation treated?

I gained weight, so the chafing in my armpits caused hyperpigmentation.

What kind of procedure should I get for this?

I have been highly recommended Pico Toning for facial pigmentation, and I am wondering if I should get the same treatment for underarm and thigh pigmentation.

Even though the underarm chafing is relatively recent, the chafing on the inner thighs has been there for quite a while. Would a procedure be effective for this area as well?

I kept putting it off because I felt a bit embarrassed and shy, and now a lot of time has passed. I'm not sure if the procedure will be effective.

Has anyone had this procedure?