IIS Error: Unrecognized configuration path 'MACHINE/WEBROOT/APPHOST/websiteName

I am trying to set IP Address and Domain Restrictions in the c# code, i am following this article, but it gives me unrecognized location error.

Error: Unrecognized configuration path 'MACHINE/WEBROOT/APPHOST/websiteName

My Code:

using (var serverManager = new ServerManager())
            {
                var config = serverManager.GetApplicationHostConfiguration();
                var ipSecuritySection = config.GetSection("system.webServer/security/ipSecurity", "websiteName");
                var ipSecurityCollection = ipSecuritySection.GetCollection();

                var addElement = ipSecurityCollection.CreateElement("add");
                addElement["ipAddress"] = @"SomeIP";
                addElement["allowed"] = false;
                ipSecurityCollection.Add(addElement);

                var addElement1 = ipSecurityCollection.CreateElement("add");
                addElement1["ipAddress"] = @"SomeIP";
                addElement1["subnetMask"] = @"255.255.0.0";
                addElement1["allowed"] = false;
                ipSecurityCollection.Add(addElement1);

                serverManager.CommitChanges();
                
            }

It gives me error after this line:

var ipSecuritySection = config.GetSection("system.webServer/security/ipSecurity", "websiteName");

Can any one tell what is wrong, or something that i have missed.