Docker-compose can't request to outside network

I’m stuck on the problems.
I know It maybe is a bad question, but
I can’t do anything.
I have some code test like that:

        [HttpGet]
        public async Task<object> Get()
        {
            try
            {
                Console.WriteLine("Start");
                HttpClient httpClient = new HttpClient()
                {
                    BaseAddress = new Uri("https://pikbest.com")
                };
                Console.WriteLine("Start call");
                var response = await httpClient.GetStringAsync("?m=download&id=123&flag=1&free_zone=0");
                Console.WriteLine("Call ok");
            } catch(Exception ex)
            {
                Console.WriteLine($"Exception: {ex.InnerException}\n{ex.Message}\n{ex.StackTrace}");
                return "Not ok";

            }
            return "Ok";
        }

When I ran with Docker only, It’s return Ok.
But when I ran with Docker-compose, It’s return Not ok.

Dockerfile:

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 as build
WORKDIR /app
COPY . ./
RUN dotnet restore
RUN dotnet publish -c Release -o ./publish

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
WORKDIR /app
COPY --from=build /app/publish .
EXPOSE 80/tcp
ENTRYPOINT ["dotnet", "testhttpclient.dll"]

And here is docker-compose.yml:

version: "3"

services:
    serverside:
        build: ./testhttpclient
        container_name: testhttpclient
        ports:
            - '80:80'

This is Console.Write logs:

testhttpclient | Start
testhttpclient | Start call
testhttpclient | Exception: System.Net.Sockets.SocketException (11): Resource temporarily unavailable
testhttpclient |    at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken)
testhttpclient | Resource temporarily unavailable
testhttpclient |    at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken)
testhttpclient |    at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean allowHttp2, CancellationToken cancellationToken)
testhttpclient |    at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken)
testhttpclient |    at System.Net.Http.HttpConnectionPool.GetHttpConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken)
testhttpclient |    at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
testhttpclient |    at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
testhttpclient |    at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
testhttpclient |    at System.Net.Http.HttpClient.FinishSendAsyncUnbuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
testhttpclient |    at System.Net.Http.HttpClient.GetStringAsyncCore(Task`1 getTask)
testhttpclient |    at testhttpclient.Controllers.WeatherForecastController.Get() in /app/Controllers/WeatherForecastController.cs:line 40
tController.Get(                                                                                                             ) in /app/Controllers/WeatherForecastController.cs:line 40

My VPS Centos info:

         Icon name: computer-vm
           Chassis: vm
        Machine ID: e3897617bcc74a32826c8ab5936dd768
           Boot ID: bf2e723b743f456a834414dbe372177b
    Virtualization: kvm
  Operating System: CentOS Linux 8 (Core)
       CPE OS Name: cpe:/o:centos:centos:8
            Kernel: Linux 4.18.0-147.5.1.el8_1.x86_64
      Architecture: x86-64

Really thank you!