You can change the startup map of your game server, by editing the commandline.
To do this, first go to your game server, in the game server control panel (https://cp.elitegameservers.net/)
- Click on Commandline Manager
- Click on the Custom Commandlines tab
- Click on new. Then configure the commandline to your likings and save it.
- Click select, next to the commandline. To enable the commandline.
Notice that the text for the enabled commandline has turned bold.