PhotonNetwork.GetRoomList() output = 0

i have make a simple main menu with a input field and a button:

public InputField NameField;
bool Pressed = true;

public void OnClick_ConfirmB()
{
    if(NameField.text != "" && Pressed == false)
    {
        Pressed = true;
        PhotonNetwork.playerName = NameField.text;

        //SceneManager.LoadScene(1);
        JoinLobby();
    }
}

void OnConnectedToMaster()
{
    Pressed = false;
}

void Update()
{
    if (Input.GetKeyDown(KeyCode.Space))
    {
        OnJoinedRoom();
    }
}

void Awake()
{
    PhotonNetwork.ConnectUsingSettings("Version 0.1");
}
void OnGUI()
{
    GUI.Label(new Rect(10, 10, 100, 100), PhotonNetwork.connectionStateDetailed.ToString());
}

void JoinLobby()
{
    PhotonNetwork.JoinLobby();
}

void OnJoinedLobby()
{
    RoomOptions Options = new RoomOptions() { IsVisible = true, IsOpen = true};
    PhotonNetwork.CreateRoom("GG", Options, TypedLobby.Default);
}

void OnJoinedRoom()
{
    Debug.Log("room length : " + PhotonNetwork.GetRoomList().Length);
}

OnClick_ConfirmB() is connected to a button…
the roomlist debug output is 0; i do not understand, plz help mi

PhotonNetwork.GetRoomList() only works in the lobby.