Error: connect ECONNREFUSED about pdf-bot HOT 1 OPEN

var LowDB = require('./src/db/lowdb.js')
var htmlPdf = require('html-pdf-chrome')

module.exports = {
  api: {
    port: 3000,
    token: 'api-token'
  },
  db: LowDB({
    lowDbOptions: {},
    path: 'pdf-storage/db/db'
  }),
  storagePath: "pdf-storage",
  webhook: {
    url: 'http://localhost:3000/webhooks/pdf'
  },
  //include this section
  generator: {
    // Triggers that specify when the PDF should be generated
    completionTrigger: new htmlPdf.CompletionTrigger.Timer(1000), // waits for 1 sec
    // The port to listen for Chrome (default: 9222)
    port: 9222 //this will be your default chrome remote debugging port
  }
}