title: HandshakeException (HandshakeException: Handshake error in client (OS Error:CERTIFICATE_VERIFY_FAILED: certificate has expired))
body: <p>While creating the agora video call application I am getting errors like this</p>
  <blockquote>
  <p>HandshakeException (HandshakeException: Handshake error in client (OS Error:CERTIFICATE_VERIFY_FAILED: certificate has expired(handshake.cc:393)))</p>
  </blockquote>
  <p>This is the line where its throwing error</p>
  <pre class="lang-dart prettyprint-override"><code>Response _response = await get(Uri.parse(link));
  </code></pre>
  <p>And my code is</p>
  <pre><code>import 'dart:convert';
  import 'package:agora_uikit/agora_uikit.dart';
  import 'package:flutter/material.dart';
  import 'package:http/http.dart'; 
  class VedioCall extends StatefulWidget {
    String channelName = &quot;test&quot;;
    VedioCall({required this.channelName});
    @override
    State&lt;VedioCall&gt; createState() =&gt; _VedioCallState();
  }
  
  class _VedioCallState extends State&lt;VedioCall&gt; {
   late final AgoraClient _client;
    bool _loading = true;
    String tempToken = &quot;&quot;;
  
    @override
    void initState() {
      getToken();
      super.initState();
    }
  
    Future&lt;void&gt; getToken() async {
      String link =
          &quot;https://Agora-Node-TokenServer.vinaym4.repl.co/access_token?channelName=${widget.channelName}&quot;;
  
      Response _response = await get(Uri.parse(link));
      Map data = jsonDecode(_response.body);
      setState(() {
        tempToken = data[&quot;token&quot;];
      });
      _client = AgoraClient(
          agoraConnectionData: AgoraConnectionData(
            appId: &quot;5a4c1108a1af4a76924c9461d120dc47&quot;,
            tempToken: tempToken,
            channelName: widget.channelName,
          ),
          enabledPermission: [Permission.camera, Permission.microphone]);
      Future.delayed(Duration(seconds: 1)).then(
        (value) =&gt; setState(() =&gt; _loading = false),
      );
    }
  
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        body: SafeArea(
          child: _loading
              ? Center(
                  child: CircularProgressIndicator(),
                )
              : Stack(
                  children: [
                    AgoraVideoViewer(
                      client: _client,
                    ),
                    AgoraVideoButtons(client: _client)
                  ],
                ),
        ),
      );
      ;
    }
  } 
  </code></pre>