how to send http post request by curl to node expressjs

app.js

var express    = require('express');
var bodyParser = require('body-parser');
var app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

app.use(function (req, res, next) {
  console.log('aeee ' +  JSON.stringify(req.body))
  next()
})

app.post('/hello', function (req, res) {
  console.log(JSON.stringify(req.body.hiee) + ' yoooooo');
  res.send('hello : ' + JSON.stringify(req.body));
});

app.listen(3000, function () {
  console.log('Example app listening on port 3000!');
});

output file with curl commands

TRY 1
-----
        with line 6
    
        TRY 1.1
        -------
        Command
        curl --data "foo=bar&baz=qux" http://localhost:3000/hello
        
        Output
        hello : {"foo":"bar","baz":"qux"}
        
        TRY 1.2
        -------
        Command
        curl -d '{"foo":"bar","baz ":"qux"}' -H "Content-Type: application/json" http://127.0.0.1:3000/hello --verbose
        
        Output
        hello : {"foo":"bar","baz":"qux"}
        
        TRY 1.3
        -------
        Command
        curl -d '{"foo":"bar","baz ":"qux"}' http://127.0.0.1:3000/hello --verbose
        
        Output
        hello : {"{\"foo\":\"bar\",\"baz \":\"qux\"}":""}       
 
TRY 2
-----
    without line 6
    
    Command
    curl -d '{"foo":"bar","baz ":"qux"}' -H "Content-Type: application/json" http://127.0.0.1:3000/hello --verbose
    
    Output
    hello : {"foo":"bar","baz":"qux"}