NIGHT is a Cardano-based token, so redeeming it requires submitting a transaction on the Cardano blockchain, where fees must be paid in ADA, not NIGHT.
These fees go to the network itself. Blockchain.com does not charge or profit from the redemption fee.
The app will show the exact ADA fee before you confirm the redemption.
If you don’t have enough ADA, redemption will be disabled until you add som