RecordFragment.java

Map<String, RequestBody> map = new HashMap<>();
                map.put("data", APIUtils.toRequestBody(new Gson().toJson(matchRequest)));

                RequestBody requestBody = RequestBody.create(
                        MediaType.parse("multipart/form-data"),
                        FileUtils.file2bytes(new File(audioFilePath))
                );
                map.put("audio\"; filename=\"match_audio.mp4\"", requestBody);

                Client.getInterface()
                        .createMatch(
                                PrefUtils.getUserToken(getActivity()),
                                map
                        )
                        .subscribe(new Subscriber<Match>() {
                            @Override public void onCompleted() {

                            }

                            @Override public void onError(Throwable e) {

                            }

                            @Override public void onNext(Match match) {
                                if (match != null) {
                                    Match.printMatchContent(match);
                                    Toast.makeText(getContext(), "Match created!", Toast.LENGTH_SHORT).show();
                                    getActivity().finish();
                                }
                            }
                        });