public string FTPHost = "ftp://xxx.xxx.xxx/myfile.json";
public string FTPUserName = "loginFTP";
public string FTPPassword = "passFTP";

public void ImportJSON () {

		Directory.CreateDirectory(Path.Combine(Application.persistentDataPath, "Backups"));
		Debug.Log("On créé le dossier Backup");

		var FilePath = Path.Combine(Application.persistentDataPath, "Backups");

		using (WebClient request = new WebClient())
		{
			request.Credentials = new NetworkCredential(FTPUserName, FTPPassword);
			byte[] fileData = request.DownloadData(FTPHost);

			Debug.Log ("OK GO On sauvegarde le fichier dans Backups");

			using (FileStream file = File.Create(FilePath))
			{
				file.Write(fileData, 0, fileData.Length);
				file.Close();
			}
			Debug.Log("Download Complete");
		}
	}