[Unit]
Description=QR Inventory Management System
After=network.target

[Service]
Type=simple
User=your-username
WorkingDirectory=/path/to/your/project
ExecStart=/usr/bin/npm start
Restart=always
RestartSec=10
Environment=NODE_ENV=production
Environment=PORT=3000
Environment=HOSTNAME=0.0.0.0

[Install]
WantedBy=multi-user.target