After complete the installation, just need to do one thing and that is the setting up the gateway.
Go to the WP-SMS > Settings > Gateways select what gateway as you need it and one-time press Save Settings.
After the page reloads, now fill the fields with your Gateway provider information like
API Key if gateway needed and press Save Settings again.
Done! now you can send an SMS from your Send SMS page.
You can check the Account Balance options too for more clearer know how much credit left on your panel.
If you want the whole configuration options, please read more next articles.