I want to get underarm laser treatment. How many sessions do I need?

I have been removing hair from my philtrum and underarms at home by myself using a home hair removal device, but I keep getting ingrown hairs and it seems like my skin is gradually becoming discolored, so I wanted to take this opportunity to visit a hospital and get it cleaned up properly.

I have received many recommendations that laser hair removal, which destroys the hair roots themselves, is less irritating to the skin and highly effective. My acquaintances have also said that after just one session, hair growth decreases significantly and maintenance becomes much easier, so I am thinking of making an appointment soon.

However, what is the typical recommended number of sessions or treatment cycle at the clinic until the hair completely stops growing or becomes very thin? I would appreciate advice from those with experience on whether about 5 sessions are sufficient, or if I should allow for 10 or more sessions.

This is a picture from when I was waxing at home.