How to load file from local NAS ( Windows and Android )

Hello

I try to read files from a my NAS.
In my configuration, i have a shared folder on a Nas at @ \sebkkun-nas/mcp_files.
A mapped a network drive on it on R:\ ( for test purpose )
using chrome I can access file:///sebkkun-nas/mcp_files/TestFichier.txt, so URL is cocrect.
But it doesn’t work in Unity.
file:///R:/TestFichier.txt : works in unity
https://upload.wikimedia.org/wikipedia/hu/8/8c/Krillin_dragon_ball_anime.png, also works.

What am I missing ?

My code :

	IEnumerator WaitForRequest(WWW www)
	{
		yield return www;
		if (www.error == null)
			Debug.Log("WWW Ok!: " + www.text);
		else
			Debug.Log("WWW Error: " + www.error);
	}

	void Start () 
	{
		string url;
		url = "file:///sebkkun-nas/mcp_files/TestFichier.txt"; // Does NOT WORK
		url = "file:///R:/TestFichier.txt"; // OK 
		url = "https://upload.wikimedia.org/wikipedia/hu/8/8c/Krillin_dragon_ball_anime.png"; // OK 
		var myFile = new WWW(url);

		StartCoroutine(WaitForRequest(myFile));

webrequest is for http protocol

so you should find out what protocol your nas is