Navigate to this URL, results in a HTML_StartRequest_t as the request commences
public static void LoadURL(HHTMLBrowser unBrowserHandle, string pchURL, string pchPostData) { InteropHelp.TestIfAvailableClient(); using (var pchURL2 = new InteropHelp.UTF8StringHandle(pchURL)) using (var pchPostData2 = new InteropHelp.UTF8StringHandle(pchPostData)) { NativeMethods.ISteamHTMLSurface_LoadURL(unBrowserHandle, pchURL2, pchPostData2); } }