public static void Main(string[] args)
    {
      CreateHostBuilder(args).Build().Run();
    }

    public static IHostBuilder CreateHostBuilder(string[] args) =>
      Host.CreateDefaultBuilder(args)
          .ConfigureServices((hostContext, services) =>
        {
          services.AddHostedService<Worker>();
        });

public class Worker : BackgroundService
  {
    private readonly ILogger<Worker> _logger;

    public Worker(ILogger<Worker> logger)
    {
      _logger = logger;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
      while (!stoppingToken.IsCancellationRequested)
      {
        _logger.LogInformation("Worker running at: {time}", DateTimeOffset.Now);
        await Task.Delay(1000, stoppingToken);
      }
    }
  }

public static IHostBuilder CreateHostBuilder(string[] args) =>
      Host.CreateDefaultBuilder(args)
       .UseWindowsService()
        .ConfigureServices((hostContext, services) =>
        {
          services.AddHostedService<Worker>();
        });

dotnet publish -c Release -o C:\WorkerPub

sc.exe create DemoWorkService binPath=C:\WorkerPub\WorkerService1.exe

sc.exe query DemoWorkService 

sc.exe start DemoWorkService 

sc.exe stop DemoWorkService 
sc.exe delete DemoWorkService 

public static IHostBuilder CreateHostBuilder(string[] args) =>
  Host.CreateDefaultBuilder(args)
    .UseSystemd()
    .ConfigureServices((hostContext, services) =>
    {
      services.AddHostedService<Worker>();
    });