Access SmartSheet API behind corporate firewall .Net C#

Question

I have just started a development to update a smart sheet document using the API.

Using the example (csharp-read-write-sheet) in the SDK reference I can update the the document as long as I am on an open internet connection, however, I cannot when I am connected to the company LAN as it is reporting a proxy authentication issue.

This is the code from the SDK

string accessToken = ConfigurationManager.AppSettings["AccessToken"];
if (string.IsNullOrEmpty(accessToken))
    accessToken = Environment.GetEnvironmentVariable("SMARTSHEET_ACCESS_TOKEN");
if (string.IsNullOrEmpty(accessToken))
    throw new Exception("Must set API access token in App.conf file");

// Get sheet Id from App.config file 
string sheetIdString = ConfigurationManager.AppSettings["SheetId"];
long sheetId = long.Parse(sheetIdString);

// Initialize client
SmartsheetClient ss = new SmartsheetBuilder().SetAccessToken(accessToken).Build();

// Load the entire sheet
Sheet sheet = ss.SheetResources.GetSheet(sheetId, null, null, null, null,     null, null, null);
Console.WriteLine("Loaded " + sheet.Rows.Count + " rows from sheet: " + sheet.Name);

Can you please advise how I can configure the API to provide a System.Net.WebProxy object to the Client API to provide authentication route through the company proxy

Answer 1

@Steve Weil's answer does not allow for you to provide user credentials.... Further research based on it though ended me up at Is it possible to specify proxy credentials in your web.config? which has now solved my issues