There are a lot of ways you can earn in cryptocurrency.
Here are the two examples of the most commonly used method
1.) Staking - Staking coins is a way to gain consistent returns on your cryptocurrency portfolio if you want to earn 1% a day. The standard holding period for staking is one to six months, but various fixed periods are available.
2.) Mining - You can profit from cryptocurrency without having to invest any capital. Bitcoin miners are rewarded with Bitcoin when they complete "blocks" of validated transactions added to the blockchain.
3. Trading - if you have enough knowledge and capital in trading, you can get a passive income from it. Just learn first before do trading to avoid huge losses if ever.