Getting null value while sending the data into mssql using node js

Question

It would be great if anyone can help me out. I am new to node.js, and I am trying to send the data into MSSQL database for my initial project, and as per project requirement I was not able to use any other DB other than MSSQL, and I am getting error value into DB while I execute the insert query. I tried to figure out the error more than a day but end up with nothing. Could anyone help me to fix this error.?

Thanks in advance.

   // Server.js


var express = require('express');
var app = express();
var port = process.env.port || 3000;

var bodyParser = require('body-parser');
// create application/x-www-form-urlencoded parser
app.use(bodyParser.urlencoded({ extended: true }));
// create application/json parser
app.use(bodyParser.json());

var ProductController = require('./Controller/ProductController')();


app.use("/app/Data", ProductController)

app.listen(port, function () {
    var datetime = new Date();
    var message = "Server runnning on Port:- " + port + "Started at :- " + datetime;
    console.log(message);
});



  //  App.js


var express = require('express');
var router = express.Router();
var sql = require("mssql");
var conn = require("../connection/connect")();

var routes = function () {
    router.route('/')
        .get(function (req, res) {
            conn.connect().then(function () {
                var sqlQuery = "SELECT * FROM ArduinoSensor";
                var req = new sql.Request(conn);
                req.query(sqlQuery).then(function (recordset) {
                    res.json(recordset.recordset);
                    conn.close();
                })
                    .catch(function (err) {
                        conn.close();
                        res.status(400).send("Error while Receive Data");
                    });
            })
                .catch(function (err) {
                    conn.close();
                    res.status(400).send("Error");
                });
        });
    router.route('/')
        .post(function (req, res) {
            conn.connect().then(function () {
                var transaction = new sql.Transaction(conn);
                transaction.begin().then(function () {
                    var request = new sql.Request(transaction);
                    request.input("start_time", sql.VarChar(50), req.body.start_time)
                    request.input("end_time", sql.VarChar(50), req.body.end_time)
                    request.input("length_time", sql.VarChar(50), req.body.length_time)
                    request.execute("Usp_InsertSensor").then(function () {
                        transaction.commit().then(function (recordSet) {
                            conn.close();
                            res.status(200).send(req.body);
                        }).catch(function (err) {
                            conn.close();
                            res.status(400).send("Error while inserting data");
                        });
                    }).catch(function (err) {
                        conn.close();
                        res.status(400).send("Error while inserting data");
                    });
                }).catch(function (err) {
                    conn.close();
                    res.status(400).send("Error while inserting data");
                });
            }).catch(function (err) {
                conn.close();
                res.status(400).send("Error while inserting data");
            });
        });

    return router;
};
module.exports = routes;

PS:- I have attached the outcome of the coding Outcome of the image