GetExternalLoginInfoAsync error method

Hi Team

I have this method and its running an error, i did have an assembly to it

using Microsoft.Owin.Security;
[AllowAnonymous]
public async Task ExternalLoginCallback(string returnUrl)
{
var loginInfo = await AuthenticationManager.GetExternalLoginInfoAsync(); // IAuthenticationManager does not contain of this method, no accessible method for it
if (loginInfo == null)
{
return RedirectToAction("Login");
}
private IAuthenticationManager AuthenticationManager
{
get
{
return HttpContext.GetOwinContext().Authentication;
}
}

How can i fix this error mates, please help its on my Controller.