Cannot connect to mac localhost from an external device

Device: MacBook Air (M1 2020)

OS: macOS Monterey Ver.12.1

I'm running a react application on localhost:8000 and I'm trying to connect with an external device.

The problem is that I get connection refused everytime.

I tried to connect with local address, local address:8000 and <name>.local but it didn't work.

I checked if the server was running properly and if the firewall was activated but the server was ok and the firewall was deactivated.

I'm wondering if there is something I can do about it. Thanks in advance.