<PackageReference Include="Relativity.Server.Identity.SDK" Version="5000.0.1" />

Relativity.Identity.V1.LoginProfileModels.TwoFactorProtocol

public enum TwoFactorProtocol
Differentiates different types of Two Factor authentication methods that are available

Use an authenticator application to provide a code

Email = 0

Deliver an authentication code to the email address associated with the account.