I do not think there are ways and means to earn passive income in crypto unless you are engaged in mining which pays you coins for your contribution in the performance of verifying transactions in the blockchain.
Even mining is no longer profitable unless you have free electricity and you have good numbers of mining system, stay passive can be done investing with project that gave staking rewards or something a like, masternodes are one of those best example, keeping numbers of coins for the network and received a rewards that can be sold as your profits but same with mining you also needs to have a decent investment to have one.