CreateMutualCertificateBindingElement throw SecurityBindingElement.CreateMutualCertificateBindingElement is not supported.

[DBA-org]

not sure why but CreateMutualCertificateBindingElement isn't implmented in security:

static public SecurityBindingElement CreateMutualCertificateBindingElement(MessageSecurityVersion version, bool allowSerializedSigningTokenOnReply)
{
if (version == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull(nameof(version));
}
throw ExceptionHelper.PlatformNotSupported("SecurityBindingElement.CreateMutualCertificateBindingElement is not supported.");
}

How can I use this secuirty biniding? what is the reason it's not supported? is there any implementation in older versions?
Pls advice, any idea, this is the only way I can consume this thrid party service.

[HongGit]

duplicate of #3424, CreateMutualCertificateBindingElement requires full message security, which is not planned yet in the near future.