I am facing issue for retrieving access token from refresh token

[Hardik Masalawala]

I am not able to get new access token using refresh token 
ERROR : The remote server returned an error: (400) Bad Request.

public static string PostMethod(string baseAddress, string data)
{
    try
    {
        HttpWebRequest request = HttpWebRequest.Create(baseAddress) as HttpWebRequest;
        string result = null;
        request.Method = "POST";
        request.KeepAlive = true;
        request.ContentType = "application/x-www-form-urlencoded;";
        string param = string.Format(data);
        var bs = Encoding.UTF8.GetBytes(param);
        using (Stream reqStream = request.GetRequestStream())
        {
            reqStream.Write(bs, 0, bs.Length);
        }
        using (WebResponse response = request.GetResponse())
        {
            var sr = new StreamReader(response.GetResponseStream());
            result = sr.ReadToEnd();
            sr.Close();
        }
        return result;
    }
    catch (Exception ex)
    {
        throw;
    }
}


private string GetToken(GmailIntegrationModel gmailIntegrationModel, string subscribedCompanyId)
{
    _logger.LogDebug("GetToken in.");
    try
    {
        //string Url = "https://www.googleapis.com/oauth2/v4/token?";
        string Url = "https://accounts.google.com/o/oauth2/token";
        var credentials = GetGmailCredentials(subscribedCompanyId);
        var data = "client_id=" + credentials.UserName + "&client_secret=" + credentials.ApiKey + "&refresh_token=" + gmailIntegrationModel.Refresh_Token + "&grant_type=refresh_token";
        var result = CommonMethod.PostMethod(Url, data);
        var res = JsonConvert.DeserializeObject<GmailIntegrationModel>(result);
        return res.Access_token;

    }
    catch (Exception ex)
    {
        _logger.LogError(ex.Message, ex);
        throw;
    }
}

[Google Ads API Forum Advisor]

Hi Hardik,
 

Thanks for reaching out to the Google Ads API team. I hope you are doing well today.
 

With regards to your concern, could you please confirm if you are using Google Ads API? If yes, you can use our client library and for you to generate a refresh token you may refer to this guide.
 

Furthermore, If you are using the rest api, you may refer to this documentation.

Regards,

Darwin Google Ads API Team

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