How many Pico Toning sessions are usually recommended? 10? 20?

Lately, my melasma and blemishes seem to have become noticeably darker, so I am looking into dermatological treatments. I am interested in Pico Toning because there are many positive reviews. I am considering it because I hear it is less irritating than regular toning and helps improve skin tone. However, I am wondering how many sessions are required to see proper results. I would like to know the typical recommended number of sessions and the treatment intervals. Since my skin tends to be sensitive, I am also concerned about severe reactions such as redness or peeling after the treatment. I would appreciate it if anyone with experience with Pico Toning could share their reviews.