INavigationService.cs

public interface INavigationService
{
    string CurrentPageKey { get; }

    void Configure(string pageKey, Type pageType);
    Task GoBack();
    Task NavigateModalAsync(string pageKey, bool animated = true);
    Task NavigateModalAsync(string pageKey, object parameter, bool animated = true);
    Task NavigateAsync(string pageKey, bool animated = true);
    Task NavigateAsync(string pageKey, object parameter, bool animated = true);
}