cannot run serve 

if npm run serve

Emitted 'error' event on WebSocketServer instance at:
    at Server.emit (node:events:526:28)
    at emitErrorNT (node:net:1357:8)
    at processTicksAndRejections (node:internal/process/task_queues:83:21) {
  code: 'EADDRINUSE',
  errno: -48,
  syscall: 'listen',
  address: '::',
  port: 9090
}
