[Concern] Age spots

It seems that age spots spread as I get older.

I regret not treating it when it first appeared.

Can it still be treated even if it has already spread?

If age spots are thinly formed on the skin, I think there might still be some effect.

I'm worried that a deep root might have formed.

How many times do I need to undergo treatment if it has to be repeated multiple times?

I'm curious about good methods to do concurrently.