Upload audio to NodeJS server

Hi all,

I need help with uploading audiofile (recorded voice stored to file) from game to NodeJs server.
In App, I am sending it via Put webrequest:

Code (CSharp):

1.  
2. byte[] myData = File.ReadAllBytes(pathToFile);;
3.         UnityWebRequest www = UnityWebRequest.Put(serverUrl, myData);
4.         yield return www.SendWebRequest();
5.  
6.         if (www.isNetworkError || www.isHttpError)
7.         {
8.             Debug.Log(www.error);
9.         }
10.         else
11.         {
12.             Debug.Log("Upload complete!");
13.         }
14.  

And In NodeJS server, I have

Code (JavaScript):

1.  
2. app.put("/uploadfile", function(req, res) {
3.      fs.writeFile("./uploads/file.wav", req, function (err) {
4.                 if (err) {
5.                 console.log("error file write");
6.                     return console.log(err);
7.                 }
8.   });
9.   });
10.  

Problem is, that every I am getting undefined req.body on server and dont have data to store.

Thanks for help