If you are wanting a fresh start on your Project Zomboid server, this guide will show you how to reset your world.
1 Login to the Kinetic Panel
2 Head to the File Manager
3 Open the .cache (It may also be called Zomboid) folder
4 You will see the Multiplayer Folder, you will delete this folder.
5 From there, you can start your server and your world would've been reset.
That is how you reset your world on the Project Zomboid server.