title: Invalid request payload input on flutter post request
body: <p>I am trying to uploading multiple files from my flutter mobile app. Here is my screenshot of the postman. This works fine on postMan. But I am getting 400 errors on the flutter mobile app. I can't find out where is the problem?
  <a href="https://i.stack.imgur.com/SEs1H.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SEs1H.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/oTiBS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oTiBS.png" alt="enter image description here" /></a></p>
  <p>Now here is the code of my flutter mobile app upload.</p>
  <pre><code> if(images.length&gt;0){
        for (int i = 0; i &lt; images.length; i++) {
          var path = await FlutterAbsolutePath.getAbsolutePath(images[i].identifier);
          String fileName = path.split('/').last;
          var file = await MultipartFile.fromFile(path, filename:fileName);
          multipart.add(file);
        }
  
        FormData imageFormData = FormData.fromMap(
            {
              &quot;feedId&quot;: value.id,
              &quot;images&quot;: multipart,
              &quot;userInformationsId&quot;: value.userInformationId
            });
        print(multipart.length);
        uploadFeedPicture(imageFormData);
    }
  
   Future&lt;String&gt; uploadFeedPicture(FormData _imageformData) async{
  
      String at = await _apiProvider.getAccessToken();
      Dio dio = new Dio();
     // dio.options.headers['accept'] = 'application/json';
    //  dio.options.headers[&quot;content-Type&quot;] = &quot;multipart/form-data&quot;;
      dio.options.headers[&quot;Authorization&quot;] = &quot;Bearer ${at}&quot;;
      dio.options.baseUrl = getBaseUrl();
  
      var _baseUrl = getBaseUrl();
       await dio.post('/api/feed/upload', data: _imageformData,  options: Options(
           followRedirects: false,
           validateStatus: (status) { return status &lt; 500; }
       ), onSendProgress: (int sent, int total) {
        print(&quot;$sent $total&quot;);
      },).then((value) {
        print(value.data);
  
        print(value.headers);
  
      }
      ).catchError((error) =&gt; print(error) );
  
  
  
  
   }
  </code></pre>
  <p>And I am getting this response.</p>
  <pre><code>{statusCode: 400, error: Bad Request, message: Invalid request payload input}
  </code></pre>
  <p>Please Help me out where is the problem? I try with change content-type but not working.</p>