我正在通过在Firebase中运行Node.js创建Line Bot，但在我的本地环境中不起作用。

当执行“ firebase提供--only功能，托管”并访问“ http：// localhost：5000 / webhook”时，将显示“无法获取/ xxx / us-central1 /应用程序/ webhook”。

index.ts

'use strict';

const functions = require('firebase-functions');
const express = require('express');
const line = require('@line/bot-sdk');

const config = {
    channelSecret: 'channelSecret',channelaccessToken: 'channelaccessToken'
};

const app = express();

app.post('/webhook',line.middleware(config),(req: any,res: any) => {
    console.log(req.body.events);
    Promise
      .all(req.body.events.map(handleEvent))
      .then((result) => res.json(result))
      .catch((result) => console.log('error!!!'));
});

const client = new line.Client(config);

async function handleEvent(event: any) {
  if (event.type !== 'message' || event.message.type !== 'text') {
    return Promise.resolve(null);
  }

  return client.replyMessage(event.replyToken,{
    type: 'text',text: event.message.text
  });
}

exports.app = functions.https.onRequest(app);

firebase.json

{
    "hosting": {
        "public": "./","rewrites": [{
            "source": "/webhook","function": "app"
        }],"ignore": [
            "firebase.json","**/.*","**/node_modules/**"
        ]
    }
}

package.json

{
  "name": "functions","scripts": {
    "lint": "tslint --project tsconfig.json","build": "tsc","serve": "npm run build && firebase serve --only functions --project golfure","shell": "npm run build && firebase functions:shell","start": "npm run shell","deploy": "firebase deploy --only functions","logs": "firebase functions:log"
  },"engines": {
    "node": "8"
  },"main": "lib/index.js","dependencies": {
    "@line/bot-sdk": "^6.8.2","express": "^4.17.1","firebase-admin": "^8.6.0","firebase-functions": "^3.3.0","ngrok": "^3.2.5"
  },"devDependencies": {
    "tslint": "^5.12.0","typescript": "^3.2.2","firebase-functions-test": "^0.1.6"
  },"private": true
}

它将如何工作？ 谢谢。