我正在部署一个将postgresql数据库连接到heroku的应用程序nodeJS，但我不知道该怎么做。

index.js-通过端口8888连接到数据库

var express = require('express');
var app = express();
app.use(express.static("public"));
app.set('view engine','ejs');
app.set("views","./views");
app.listen(process.env.PORT || 3000);


var pg = require('pg');
var config = {
  user: 'postgres',database: 'book',password: 'hovupham0311',host: 'localhost',port: '8888',max: 10,idleTimeoutMillis: 30000,}


var pool = new pg.Pool(config);

app.get("/",function(req,res){

    pool.connect(function(err,client,done) {
        if (err) throw err
        client.query('SELECT * FROM sach',function(err,result) {
          done();
          if (err) {
              res.end();
            return console.error(err);
          } 
          res.render("home",{data:result});
        });
      });

})

这是package.json文件

{
  "name": "demo","version": "1.0.0","description": "","main": "index.js","scripts": {
    "start": "node index.js"
  },"author": "","license": "ISC","dependencies": {
    "body-parser": "^1.19.0","ejs": "^2.7.1","express": "^4.17.1","multer": "^1.4.2","pg": "^7.12.1"
  }
}

，一切都可以在本地主机上运行。有人可以帮我吗！