How many treatments are usually recommended for melasma?

As the weather gets warmer and I spend more time outdoors, the melasma under my eyes and around my cheekbones feels darker than before, so I am looking into melasma treatment. I have heard that unlike blemishes, which are treated once and then forgotten, melasma requires consistent management based on skin condition, so I am wondering how to set up a treatment plan from the start.

I would like to know how many sessions are usually recommended, especially when starting melasma treatment for the first time. Since the extent and color of melasma vary from person to person, I am curious whether the recommended number of sessions is fixed from the start, or if the frequency is adjusted after a few treatments based on skin reaction and the degree of improvement.

I would also like to know if I need to continue melasma treatment even after it has faded to a certain extent, or if I can simply extend the intervals and focus on maintenance afterwards. I am also curious how the recommended number of sessions changes if I include care to prevent the melasma from darkening again. During the initial consultation, could I have my current condition assessed and receive guidance on the approximate number of treatments and a management plan?