Login to the Kinetic Panel.
Stop the server.
Go to the File Manager.
Navgaite to .local > share > Euro%20Truck%20Simulator%202 > server_config.sii.
Change the desired Settings.
Save
Start the server.
Euro Truck Simulator 2 guide
How to configure your Euro Truck Simulator 2 Server
This guide will cover how to configure your server from Max players, Vehicles, AI, Traffic, and Damage and many other options to customise your Server.