Upload large video file chunks use retrofit2 (Android)

Question

Sorry for my english. I need upload large files to server. I use retrofit2 for this. Now i upload files without chunks, i send single file. Like this:

interface

@Multipart
@POST("/api/upload")
Observable<UploadVideoResponse> uploadVideo(@Header("Authorization") String userToken,
                                            @Part MultipartBody.Part video);

like this i create MultipartBody.Part video

 public static MultipartBody.Part getMultipartVideoBody(String pathVideo) {
        try {
            File videoFile = getFile(pathVideo);
            RequestBody videoBody = RequestBody.create(MediaType.parse("video/*"), videoFile);
            String fileName = videoFile.getName();
            return MultipartBody.Part.createFormData("video", fileName, videoBody);
        }catch (Exception e){
            Log.e("File ", e.getMessage());
            return null;
        }
    }

In the server use laravel-chunk-upload and for chunks upload in front-end use like this:

dropzoneOptions: {
                   url: '/uploadtest',
                   dictDefaultMessage: 'Click here',
                   chunksUploaded: function (file, done) {
                       done()
                   },
                   thumbnailWidth: 150,
                   maxFilesize: 250,
                   chunking: false,
                   chunkSize: 1000000, // Bytes
                   required: true,
                   maxFiles: 1,
                   acceptedFiles: 'video/*',
                   headers: {
                       'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
                   }
               },

Now i cant understend how i can upload large video file from chunks. Please give me some advice