Javascript 在node.js中使用js链接hbs文件

我正在制作一个购物车程序，其中我想将我的其他文件链接到我的主购物车，所以我进入我的app.js并尝试了。当我尝试链接它时，显示错误404，这是我的app.js

var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var hbs = require('hbs');
var session = require('express-session');

var index = require('./routes/index');

var app = express();


app.set('views', path.join(__dirname, 'views'));
hbs.registerPartials(__dirname + '/views/partials');
app.set('view engine', 'hbs');

app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(session({
  secret: 'secret',
  resave: false,
  saveUninitialized: true
}))
app.use(express.static(path.join(__dirname, 'public')));

// res.locals is an object passed to hbs engine
app.use(function(req, res, next) {
    res.locals.session = req.session;
    next();
});

app.use('/', index);
**app.use('/shop', function(req, res) {
  res.sendFile(__dirname, 'shop.hbs');
})**```

Please tell how to link