Force the SecurityGateway web interface to only accept connections over SSL only

1. Choose Setup / Users -> System -> HTTP Server.
   
2. Remove any HTTP ports and ensure the HTTPS port you define is the one you want to use to access HTTPS connections only.
   
3. Choose Save to apply the change.

Alternatively, retain the HTTP port, but tick Redirect HTTP requests to HTTPS to ensure all requests on the HTTP port are automatically redirected to the HTTPS port.