How many laser treatments do I usually need to see noticeable results?

In the past, my skin tone was quite clear even when I applied sunscreen haphazardly, but at some point, blemishes resembling melasma started appearing around my cheekbones and cheeks, and I can visibly see them getting darker. Because of the pigmentation appearing all over my face, my overall skin tone looks dull and patchy, so I frequently hear people ask why I look so tired. I've been using vitamin ampoules that are supposed to be good for whitening and doing face masks regularly, but...

There were parts that couldn't be covered even with makeup.

I'm thinking of starting proper pigmentation treatment, like a toning laser, at a dermatology clinic before it gets any darker.

How many laser treatments do I usually need to see noticeable results for melasma or blemishes? Also, since there are various types, I am wondering which laser would be the best fit for my condition.