How do I put a Node.js app online on my laptop?

With Node.js I developed a chat app that I now want to share with certain devices, like a kind of local server at home.

Is there a way to release this with Windows only through Command Promt? And can I also set which MAC addresses have access to it?

I'm assuming you've created a website, right?

If you start it on your Windows PC and the Windows Firewall is configured correctly, it should be accessible via the IP of your computer in the internal network. Of course, it assumes that the computer is running all the time. Here I would recommend a Raspberry Pi. Then you can connect it via WLAN / LAN, start the Node.js app and have access all the time without the PC having to remain switched on.