AddHttpClient with HttpClientHandler, 401 unauthorized C#

I try to use service.AddHttpClient to create HttpClient and DI into my other services, but HttpClient need to be set credential informations. Here is my step,

1. Startup.cs

    services.AddHttpClient("ServiceOne", x => {})
            .ConfigurePrimaryHttpMessageHandler(() => 
            {    var handler = new HttpClientHandler(){ 
                    UseDefaultCredentials = true,
                    Credentials = new NetworkCredential("account", "password")
                    };
   
                 return handler;
            });
   

2.ServiceOne.cs

public class ServiceOne : IService
{
 private readonly IHttpClientFactory _clientFactory;
}

public ServiceOne (IHttpClientFactory clientFactory)
{
   this._clientFactory = clientFactory;
}

public string SomeFunction ()
{
  var request = new HttpRequestMessage(HttpMethod.Get,"http://uri");
  var client = _clientFactory.CreateClient("ServiceOne");
  var response = client.SendAsync(request).GetAwaiter().GetResult();
}

I received 401 Unauthorized, it seems the HttpClientHandler not be set correct. Hope someone could help me this question, Thanks.