I want to set default page signin form but as I try to change it i'm getting errors and if i set Auth.razor its show me auth layout but i'm not able to set signin page as default page for app

@using Solution.UI.Pages.Error;
@using Layout
<Router AppAssembly="@typeof(App).Assembly">
<Found Context="routeData">
<RouteView RouteData="@routeData" DefaultLayout="@typeof(DefaultDarkSidebar)" />//Signin
<FocusOnNavigate RouteData="@routeData" Selector="h1" />
</Found>
<NotFound>
<PageTitle>Not found</PageTitle>
<LayoutView Layout="@typeof(SystemLayout)">
<PageNotFound></PageNotFound>
</LayoutView>
</NotFound>
</Router>