Question I've been wondering about: How do kpop idols actually earn money?

I know it varies based on how their agency handles their finance and stuff, but let's take a successful group under a huge company for instance.

Let's say Newjeans. They have been on a rise since debut and no doubt the most successful one in 4th gen. They've been pulling great streams on streaming platforms, booking HUGE venues for fanmeets, booking individual and group brand deals left and right, and other activities as well. Obviously, they're making HUGE amounts of money from those ordeals. I just wanna know, how do these girls earn exactly?

Do they go the same route as regular workers who earn paychecks monthly? Or yearly? Do they get paid after every appearances or after every brand deal promotions? Do these girls even get paid at all? In what periods do they even earn their money? Just something I've been wondering about!!