How to get ad_units list via Google Adsense Management API from ASP.NET 5 controller?

Question

Google

In startup.cs:

services.AddAuthentication(options => options.SignInScheme = CookieAuthenticationDefaults.AuthenticationScheme);
app.UseGoogleAuthentication(options =>
{
options.ClientId = "560027070069-37ldt4kfuohhu3m495hk2j4pjp92d382.apps.googleusercontent.com";
options.ClientSecret = "n2Q-GEw9RQjzcRbU3qhfTj8f";
options.Events = new O =>
{ AuthEventxError ( ) .Response.Redirect("/error?ErrorMessage=" + UrlEncoder.Default.Encode(ctx.Error.Message)); ctx.HandleResponse();
return Task.FromResult(0);
}
};
});

Get-request in controller returns 401(Unauthorized)
What am I doing wrong?