Content type 'application/octet-stream' not supported POST 'Mono<FilePart> JAVA

Question

I'm making a POST request to this endpoint

 @PostMapping(value = "attachments",consumes = {MediaType.MULTIPART_FORM_DATA_VALUE})
    public ResponseEntity<Mono<AttachmentResponse>> upload(@RequestPart("file") Mono<FilePart> file,
                                                           @RequestPart("Info") String req,
                                                           Authentication authentication) {

the request I'm making is this

  HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers.add(AUTHORIZATION, tokenRetornado);

        MultiValueMap<String, String> multiValueMap = new LinkedMultiValueMap<>();
        multiValueMap.add("Content-Type", "multipart/form-data");
        headers.addAll(multiValueMap);

        MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
        body.add("attachment", blob);
        body.add("attachmentInfo", getAttachmentInfo("customer"));


        HttpEntity<MultiValueMap<String, Object>> requestEntity =
                new HttpEntity<>(new LinkedMultiValueMap<>(), headers);
        requestEntity.getBody().addAll(body);

            webClient.post()
                    .uri("http://localhost:8082/receiver/attachments")
                    .contentType(MediaType.MULTIPART_FORM_DATA)
                    .contentType(MediaType.APPLICATION_OCTET_STREAM)
                    .contentType(MediaType.APPLICATION_JSON)
                    .body(BodyInserters.fromMultipartData(body))
                    .retrieve()
                    .bodyToMono(AttachmentResponse.class)
                    .block();

after making the request I get the error 415 Unsupported Media Type from POST http://localhost:8082/receiver/attachments