How Do I Download an Entire Directory From a Server in Unity?

Ultimately, I my goal is to just update my StreamingAssets Data directories, via directories on the web server.

I am trying to download an entire directory of files from a web server to be able to update the files for my game. (folder structure matters)

Currently, the files I am using have an organized hierarchy structure inside of my StreamingAssets folder that are read during runtime. As the game starts, it compares a versioning text file to the server's versioning and if they differ, it should update to the server's files.

Now I am successfully able to get that single file and compare its text, however I am unaware as to how I can get ahold of the entire directory of files and their subfolders to update and replace the files in my StreamingAssets data.

Hopefully I am asking a dumb question, but also there may be an entirely better answer to achieve my goal, please let me know where to look/ what you guys would all do.

This is how I get my Versioning Check:

IEnumerator readOnlineCardVersion()
{
       VersionTextFile = UnityWebRequest.Get("http://www.myserver.com/SteamingAssets/FlashCards_Version.txt");
        if (workingOnline)
        {
            UnityWebRequest www = VersionTextFile;
            yield return www.SendWebRequest();

            if (www.isNetworkError || www.isHttpError)
            {
                Debug.Log(www.error);
            }
            else
            {
                // Show results as text
                Debug.Log(www.downloadHandler.text); //.downloadHandler.);

                // Or retrieve results as text
                onlineCardVersion = www.downloadHandler.text;
            }
        }
        else
        {
            #region LocalTest
            //Read the text from directly from the test.txt file
            StreamReader reader = new StreamReader(onlineFolderPath + "StreamingAssets/FlashCards_Version.txt");
            using (reader)
                onlineCardVersion = reader.ReadToEnd();
            //Debug.Log("." + onlineCardVersion + ".");
            reader.Close();
            #endregion
        }
}

Basically, I can retrieve individual files simply, but how can I recursively acquire all files in a particular web directory.