BlazorStart/Start/Client/App.razor

<Fluxor.Blazor.Web.StoreInitializer />

<CascadingAuthenticationState>
    <Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="@true">
        <Found Context="routeData">
            <AuthorizeRouteView RouteData="@routeData">
                <NotAuthorized>
                    @if (!context.User.Identity?.IsAuthenticated ?? false)
                    {
                        <RedirectToLogin />
                    }
                    else
                    {
                        <p>You are not authorized to access this resource.</p>
                    }
                </NotAuthorized>
            </AuthorizeRouteView>
        </Found>
        <NotFound>
            <p>Sorry, there's nothing at this address.</p>
        </NotFound>
    </Router>
</CascadingAuthenticationState>