<PackageReference Include="NETStandard.Library" Version="2.0.2" />

System.Security.Cryptography.X509Certificates.X509IncludeOption

public enum X509IncludeOption
namespace System.Security.Cryptography.X509Certificates { public enum X509IncludeOption { EndCertOnly = 2, ExcludeRoot = 1, None = 0, WholeChain = 3 } }