Install a NeoForge 21.1.4 (MC 1.21.1 ) server through the Control Panel (Servers → Select your server → Game servers → Add Game Server → NeoForge 21.1.4 (MC 1.21.1 ))
Great! Needed a server to play with a couple buddies with and this served great! Easy to use and simple to get running. Web interface is super easy and simple to use. Really Enjoy it.