there are two ways to get passive income at this time, that is you can staking altcoin that you have (although only a few altcoin can staking) or you can "play to earn" (like playing Axie Infinity), because the income from Axie Infinity is very big, although at this time the capital to play Axie Infinity is also very big, but of course I prefer staking than "play to earn", because the risk is smaller than if you choose "play to earn" (I'm afraid it's just hype for a while).