Error while connecting web socket "Error while connecting. Message: Unable to connect to the remote"

once "ticker.Connect();" this line is executed its control flow gets into "OnError" method with error message as "Error while connecting. Message: Unable to connect to the remote server", version is 3.0.0

how to debug the code, i am using zerodha kite connect sdk

Both the apikey and access token is correct but every time its showing this errors
Error: Error while connecting. Message: Unable to connect to the remote server
Error: Error while connecting. Message: The remote server returned an error: (403) Forbidden.
Closed ticker

i am simply executing this method provided in Zerodha reference code, the api key and access token passed is also correct but as soon as ticket.connect() is executed following errors pop up in console, version of library is 3.0.0
is there any step i am missing or forgot to do?

Error message
Error: Error while connecting. Message: Unable to connect to the remote server
Error: Error while connecting. Message: The remote server returned an error: (403) Forbidden.
Closed ticker

Code of a .net console app

static void Main(string[] args)
{
initTicker();
}
private static void initTicker()
{
ticker = new Ticker(//api key, // access token);

ticker.OnTick += OnTick;
ticker.OnReconnect += OnReconnect;
ticker.OnNoReconnect += OnNoReconnect;
ticker.OnError += OnError;
ticker.OnClose += OnClose;
ticker.OnConnect += OnConnect;
ticker.OnOrderUpdate += OnOrderUpdate;

ticker.EnableReconnect(Interval: 1, Retries: 1);

ticker.Connect();


// Subscribing to NIFTY50 and setting mode to LTP
ticker.Subscribe(Tokens: new UInt32[] { 256265 });
ticker.SetMode(Tokens: new UInt32[] { 256265 }, Mode: Constants.MODE_LTP);
}