There are a few different ways to make money streaming on Twitch. The most common way is through donations and subscriptions. You can also make money by selling products, such as t-shirts and mouse pads, through your Twitch channel. Finally, you can also make money by becoming a Twitch partner and earning a share of the ad revenue generated from your channel.
To learn more about how to make money streaming on Twitch, check out this article from the Twitch blog.