DevDefined - Get QBD Vendors

//using DevDefined.OAuth.Consumer;
//using DevDefined.OAuth.Framework;

protected void GetVendors()
{
    OAuthConsumerContext consumerContext = new OAuthConsumerContext
    {
        ConsumerKey = ConfigurationManager.AppSettings["consumerKey"].ToString(),
        SignatureMethod = SignatureMethod.HmacSha1,
        ConsumerSecret = ConfigurationManager.AppSettings["consumerSecret"].ToString()
    };

    OAuthSession oSession = new OAuthSession(consumerContext, "https://oauth.intuit.com/oauth/v1/get_request_token",
                            "https://workplace.intuit.com/Connect/Begin",
                            "https://oauth.intuit.com/oauth/v1/get_access_token");

    oSession.ConsumerContext.UseHeaderForOAuthParameters = true;

    oSession.AccessToken = new TokenBase
    {
        Token = Session["accessToken"].ToString(),
        ConsumerKey = ConfigurationManager.AppSettings["consumerKey"].ToString(),
        TokenSecret = Session["accessTokenSecret"].ToString()
    };

    IConsumerRequest conReq = oSession.Request();
    conReq = conReq.Get();
    conReq = conReq.ForUrl("https://services.intuit.com/sb/vendor/v2/508053445");
    try
    {
        conReq = conReq.SignWithToken();
    }
    catch (Exception ex)
    {
        throw ex;
    }

    string header = conReq.Context.GenerateOAuthParametersForHeader();

    string serviceResponse = conReq.ReadBody();

}