What does this feature means and how does it works?

Hello.
What does “Crypto Rewards: Earn rewards in different crypto currencies” means and how does this works? It is visible in the comparison list for Black and Metal accounts.
Thank you.

Crypto Rewards are an entirely new product enabling Curve premium (Black and Metal) customers to switch the type of cashback they earn to cryptocurrency tokens, with the Curve X tier, only being able to earn Crypto Rewards in Bitcoin.Find out about upgrading your subscription here

Crypto Rewards is an opt-in feature, totally exclusive to our premium customers. If turned on, it allows you to earn crypto tokens both on your Curve Rewards offers, as well as on purchases eligible for 1% Curve Cashback with 3 or 6 selected retailers for Black and Metal customers.

See more here: Crypto Rewards