POST

    QFile *file = new QFile("/path/image.jpg");
    file->open(QIODevice::ReadOnly);

    QUrl url("http://localhost:8888");
    QNetworkRequest request;
    request.setUrl(url);

    QHttpMultiPart *multipart = new QHttpMultiPart(QHttpMultiPart::FormDataType);

    QHttpPart image;
    image.setHeader(QNetworkRequest::ContentLengthHeader, QVariant(file->size()));
    image.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("name=\"image\"; filename=\"name.jpg\""));
    image.setBodyDevice(file);
    file->setParent(multipart);

    multipart->append(image);

    QNetworkAccessManager manager;
    QNetworkReply *reply = manager.post(request, multipart);
    multipart->setParent(reply);

    connect(reply, &QNetworkReply::finished, this, &ServerRest::replyTEST);