<PackageReference Include="System.Security.Cryptography.Cng" Version="5.0.0" />

System.Security.Cryptography.ECKeyXmlFormat

public enum ECKeyXmlFormat
Defines XML serialization formats for elliptic curve keys.
Rfc4050 = 0

An XML serialization format described in RFC 4050, "Using the Elliptic Curve Signature Algorithm (ECDSA) for XML Digital Signatures."