Server Side Blazor (Preview 6) - is it possible to

Question

For a Blazor server hosted page - is it possible to require authentication? Based on the following documentation:

https://docs.microsoft.com/en-au/aspnet/core/security/authorization/policies?view=aspnetcore-3.0

I've added the following to my Startup.cs:

public void ConfigureServices(IServiceCollection services)
{
  services.AddMvc().SetCompatibilityVersion( CompatibilityVersion.Version_2_2 );

  services.AddAuthorization(options =>
  {
      options.AddPolicy("Private", policy => policy.RequireAuthenticatedUser() );
  });
}

And here's what I've put at the top of the fetchdata page:

@page "/fetchdata"
@using HollyTest.Data
@inject WeatherForecastService ForecastService
@attribute [Authorize(Policy="Private")]

<h1>Weather forecast</h1>

<p>This component demonstrates fetching data from a service.</p>

Can someone tell me if I'm on the right track?