C# SelfHost how to restrict all external requests?

Question

I have a program that works as a background service. It hosts a self-hosted service. But there is an issue. When I host this service it becomes available for all locale network. And, everyone in the same network can get access to this API. Here is how I host the service :

First I Register the url with netsh

string frm = string.Format(@"http add urlacl url={0}:{1} user={2}\{3}", address, port, domain, user);
            Process.Start(new ProcessStartInfo("netsh", frm)
            {
                Verb = "runas",
                CreateNoWindow = true,
                WindowStyle = ProcessWindowStyle.Hidden,
                UseShellExecute = true
            }).WaitForExit();

Then I host the service

 _hostConfiguration = new ExtendHttpSelfHostConfiguration(
                string.Concat(url, ":", port))
            {
                MaxReceivedMessageSize = int.MaxValue,
                MaxBufferSize = int.MaxValue 
                
            };
            _server = new HttpSelfHostServer(_hostConfiguration);
            _hostingTask = _server.OpenAsync();
            _hostingTask.Wait();

The structure of ExtendHttpSelfHostConfiguration is :

public class ExtendHttpSelfHostConfiguration : HttpSelfHostConfiguration
    {
        /// <summary>
        /// 
        /// </summary>
        /// <param name="baseAddress"></param>
        public ExtendHttpSelfHostConfiguration(string baseAddress) : base(baseAddress) => Configure();
        /// <summary>
        /// 
        /// </summary>
        /// <param name="baseAddress"></param>
        public ExtendHttpSelfHostConfiguration(Uri baseAddress) : base(baseAddress) => Configure();

        

        /// <summary>
        /// 
        /// </summary>
        /// <param name="httpBinding"></param>
        /// <returns></returns>
        protected override BindingParameterCollection OnConfigureBinding(HttpBinding httpBinding)
        {
           
            if (BaseAddress.ToString().ToLower().StartsWith("https://"))
            {
                httpBinding.Security.Mode = HttpBindingSecurityMode.Transport;
            }
            return base.OnConfigureBinding(httpBinding);
        }

        private void Configure()
        {
            ConfigureCors();
            ConfigureRoutes();
            ConfigureFormatters();
            ConfigureFilters();
            ConfigureProviders();
            ConfigureSwagger();
            ConfigureLogger();
        }



        private void ConfigureSwagger()
        {
            #if DEBUG
            this.EnableSwagger(c =>
            {
                c.SingleApiVersion("v1", "Host services");
                c.DescribeAllEnumsAsStrings();
                c.IncludeXmlComments(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, string.Concat(Assembly.GetExecutingAssembly().GetName().Name + ".xml")));
            }).EnableSwaggerUi();
            #else
            #endif
        }

        private void ConfigureLogger() => XmlConfigurator.Configure();

        private void ConfigureProviders() => FluentValidationModelValidatorProvider.Configure(this);

        private void ConfigureFilters() => Filters.Add(new ValidationFilter());

        private void ConfigureCors() => this.EnableCors(new EnableCorsAttribute("*", "*", "*"));

        private void ConfigureRoutes() => this.MapHttpAttributeRoutes();

        private void ConfigureFormatters()
        {
            Formatters.JsonFormatter.SupportedMediaTypes.Clear();
            Formatters.XmlFormatter.SupportedMediaTypes.Clear();
            Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/json"));
            Formatters.XmlFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/xml"));
            Formatters.OfType<JsonMediaTypeFormatter>().First().SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
        }
    }

It works completely for local machine.
But when I scan the network nmap can detect this port.

The problem is how to make it work only on the computer. The others shouldn't get access to this port. As I understand for doing this, instead of 0.0.0.0 there should be 127.0.0.1.

How can I solve this problem?

How the other services in my PC works like that?