Example of disposing an instance created inside the ConfigureServices method

Startup.cs

public class StartUp
{
    public StartUp()
    {
    }
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSingleton<ISomeDisposable>(new SomeDisposable());
    }

    public void Configure(IApplicationBuilder app, IHostApplicationLifetime applicationLifetime, IEnumerable<ISomeDisposable> someDisposables)
    {
        applicationLifetime.ApplicationStopping.Register(() =>
        {
            foreach (var disposable  in someDisposables)
            {
                (disposable as IDisposable)?.Dispose();
            }
        });
    }
}