How do you change lobby on Minecraft?

To change the lobby in minecraft, you need to access the server settings if you are an administrator. For a Minecraft server, you can modify the server.properties file to change the default world or lobby by adjusting the "level-name" property. Alternatively, if you're using a plugin or a server management tool like Multiverse, you can create or switch to a different lobby world directly through the plugin's commands. Make sure to restart the server for the changes to take effect.