I make project mesh upload Donwload project and error is occured upload download

I make project mesh upload Donwload project and error is occured upload download

uploading succesfully but i don't know downloading

I convet mesh to binary file and upload

I download binary file and convert binary to mesh

2 error

1.I uploaded file but website Gamemanger/content/filemangement is not displayed

2. I download file but I do not know whether it is the correct file or not

i think that is not correct file

the reason is MeshSerializer doesn't work

MeshSerailizer worked fine without upload,download

This is upload cord

public void UploadFileToCDN
(string key, byte[] content, string contentType = "binary/octet-stream")
    {
        GetUploadUrl(key, contentType, presignedUrl =>
        {
            PutFile(presignedUrl, content, contentType);
        });
    }


    void GetUploadUrl(string key, string contentType, Action<string> onComplete)
    {
        PlayFabAdminAPI.GetContentUploadUrl(new GetContentUploadUrlRequest()
        {
            ContentType = contentType,
            Key = key
        }, result => onComplete(result.URL),
        error => Debug.LogError(error.GenerateErrorReport()));
    }
 void PutFile(string presignedUrl, byte[] content, string contentType = "binary/octet-stream")
    {
        List<IMultipartFormSection> formData = new List<IMultipartFormSection>();
        formData.Add(new MultipartFormDataSection("field1=foo&field2=bar"));
        formData.Add(new MultipartFormFileSection(content));

        UnityWebRequest www = UnityWebRequest.Post(presignedUrl, formData);


        if (www.isNetworkError || www.isHttpError)
        {
            Debug.Log(www.error);
        }
        else
        {
            Debug.Log("Form upload complete!");
        }
    }

this is cord Download cord

 public void DownloadFileFromCDN(string key)
    {

        GetDownloadUrl(key, presignedUrl =>
        {
          MeshSerializer.DeserializeMesh(GetFile(presignedUrl), GetComponent<MeshFilter>().mesh);
        });
    }


    void GetDownloadUrl(string key, Action<string> onComplete)
    {
        PlayFabClientAPI.GetContentDownloadUrl(new GetContentDownloadUrlRequest()
        {
            Key = key,
            ThruCDN = true
        }, result => onComplete(result.URL),
        error => Debug.LogError(error.GenerateErrorReport()));
    }


    byte[] GetFile(string preauthorizedUrl)
    {
        UnityWebRequest www = UnityWebRequest.Get(preauthorizedUrl);
        // yield return www.SendWebRequest();


        if (www.isNetworkError || www.isHttpError)
        {
            Debug.Log(www.error);
            return null;
        }
        else
        {
           byte[] results = www.downloadHandler.data;
            return results;
        }
        
    }