API:AddDnssec is supported only through the AWS Management Console.
Choose Key type: 257 - KSK
Choose Algorithm: 13 - ECDSAP256SHA256
If your registrar isn't Amazon Route 53, then register the KSK public key and DS record with your registrar. The domain registrar forwards the public key and the algorithm to the registry for the top-level domain (TLD). Note that the DS record is a digest of the KSK public key.