The security of DERA chain (and any other blockchain) depends on it decentralization. By becoming a Validator and participate in blockchain consensus, you will contribute to the security of DERA chain, hence will be eligible for reward.
Navigate to Staking site and follow the guideline to register your node as validator. After successful registration, your node will be a Validator and start to accrue rewards.
Note on operations
The validator must maintain a non-zero AVAX balance on P-chain to be eligible for participate in the validator set. Thus please monitor closely your node AVAX balance and keep it sufficient. You can monitor the balance on the Staking site.