Normally, when you play a script from your Loadster web dashboard, Loadster generates the traffic from a shared engine on the public internet. Of course, this doesn't work so well when your site is on a private network and therefore unreachable.
No problem! You can run your own Loadster Engine on the same network as the site you're testing, or on a network that is allowed to route traffic to it, and select that self-hosted engine as your script player.
Follow the instructions in Testing with Loadster Engine to install and configure your engine. For the purposes of scripting, you only need one, but if you need to run large load tests you can install more.
Loadster Engine is included with your Loadster Plan or Loadster Fuel at no additional cost.
After you've registered your new engine, go to Settings and select it as your Single-User Script Player.
This is a global setting, so the next time you play a script, the traffic will be generated from your self-hosted engine instead of the public one.