Download the server.jar file from Minecraft's official site. Players can find the server.jar file for the latest version on the site. After downloading, make sure the file name is minecraft_server ...

What you see in that sample file is all you need to configure that static IP address. Do notice, you aren’t setting the address is the same fashion as you did with Ubuntu 16.04.

The next thing you'll want to do is download 1.21's jar file. This is the server file itself. Put this into its own folder, properly named, so that you can remember it as your Minecraft 1.21 server.

Jack Wallen walks you through the process of giving a standard user sudo privileges so they can set a static IP address on Debian server.