How To Create a Flat World?
Head over to the Game Panel and stop your server.

Navigate to the "Properties -> World" tab and find the "level-type" option.

Change the "level-type" option to "minecraft\:flat" (default: minecraft\:normal).
You need to generate a new world; find the box "level-name" and change it to your desired name (default: world).

Done! You can now start your server to generate the flat world.
🎉 Congratulations, you've successfully created a flat world. If you have any issues or concerns, please contact us through the ticket system.