Claim Rewards, not crv, but the tokens are there. ... @curvefi

Yes, if you have earned 3CRV rewards from staking, you can lock them in the Curve Vault to boost your yields. Locking your rewards in the Curve Vault will increase the amount of rewards you can earn by up to 20%. You can do this by going to the Curve Vault tab in your wallet, then selecting the amount of 3CRV tokens that you want to lock. After you have selected the amount, click the “Lock” button to start the process. You can also choose to unlock your rewards at any time.

what rewards you want to claim?

You mean 3CRV rewards that you get for staking?