ShellDI.cs

static class ComicRouteFactory
{
	public static RouteFactory Create<TPage, TViewModel>() 
		where TPage : Page, new()
		where TViewModel : BaseViewModel
	{
		return new Factory<TPage, TViewModel>();
	}

	private class Factory<GPage, GViewModel> : RouteFactory
		where GPage : Page, new()
		where GViewModel : BaseViewModel
	{
		public override Element GetOrCreate()
		{
			var page = new GPage();

			var vm = ServiceProvider.GetService<GViewModel>();

			page.BindingContext = vm;

			return page;

		}
	}
}

// Registering the route 
void RegisterRoute()
{
	Routing.RegisterRoute(nameof(ComicsViewModel), ComicRouteFactory.Create<ComicPage, ComicsViewModel>());
}

//Register ViewModel
public static MauiApp CreateMauiApp()
{
	var builder = MauiApp.CreateBuilder();
	// ...

	builder.Services.AddSingleton<ComicService>();

	builder.Services.AddTransient<ComicsViewModel>();

	return builder.Build();
}