This extension is only a system that sends SMS based on your SMS Gateway API configuration. This extension will not work without an SMS Gateway. SMS Gateway Addon modules are available here (http://www.huntbee.com/extensions-modules/sms-gateway-addons-for-opencart) and also on opencart marketplace, and if you want a module for your preferred SMS Gateway, it will be developed on demand.
Support: email@example.com . Installation and template customization support is FREE