Esp32 error 400 upload spiffs wav file to web server using http post

Projects Networking, Protocols, and Devices
8

with this modification to the code iam able to copy the file to the server but it is corrupted. the file have 33kb and inside have the wav header but cant play it.

HTTPClient client;
  client.begin("http://192.168.1.112:5000/upload");
  String boundary = "----WebKitFormBoundary7MA4YWxkTrZu0gW";
  client.addHeader("Content-Type", "multipart/form-data; boundary=" + boundary);
  String body = "--" + boundary + "\r\n";
  body += "Content-Disposition: form-data; name=\"file\"; filename=\"recording.wav\"\r\n";
  body += "Content-Type: audio/wav\r\n\r\n";
  body += file.readString();
  body += "\r\n--" + boundary + "--\r\n";
  // Calculate the content length
  int contentLength = body.length();
  // Set the Content-Length header
  client.addHeader("Content-Length", String(contentLength));
  int httpResponseCode = client.sendRequest("POST", body );
    
  Serial.print("httpResponseCode : ");
  Serial.println(httpResponseCode);