Starting a temporary instance of N8N accessible via IPv4 over the local network

N8n by default binds to localhost, and even binding it to listen on all interfaces, it still by default listens only for IPv6. You also may want to tell it to not use the Secure Cookie if you don't want to set up an SSL certificate or sign up for their cloud service. Make sure you only have it reachable on the local network if you do this, you don't want to open your instance to the entire world.

N8N_SECURE_COOKIE=false N8N_HOST=0.0.0.0 N8N_LISTEN_ADDRESS=0.0.0.0 npx n8n

Remember to open port 5678 on the machine's firewall if necessary.