best ways to earn legal money in the internet?

One way i make some side cash is by selling coins on games like madden and FIFA. Generally easy to get coins on fifa, im still not that used to the madden market. Coins on those games usually go for like $10 for 100,000 coins.

There was other games like rocket league that worked but that kind of died down with everyone that plays that game knows about trading. Was fun when everyone was a noob lol.