Setting a world border is useful if you want to keep players close to spawn or reduce storage usage.
Server Console
Log In to the Control Panel ↗
Select Your Server
Set the World Border Size
In the Console, type worldborder set [diameter], where [diameter] is the total width of the world border in blocks.
For example, worldborder set 1000 creates a world border with a radius of 500.
Set the World Border Center (Optional)
In the Console, type worldborder center [x] [z] to set the center coordinates.
A diameter of 1000 means the world has a radius of 500 blocks from the center.
You have successfully configured the world border on your server.