Insert data through SPARQL over HTTP POST request from node js

I am using 'request' module in my node app to POST data in ontology model which resides in a fuseki server. I am using the following code:

var request = require('request');
var querystring = require('querystring');

var myquery = querystring.stringify({update: "PREFIX test:<http://www.semanticweb.org/muhammad/ontologies/2017/2/untitled-ontology-14#> INSERT { ?KPIs test:hasValue 2009} WHERE { ?KPIs test:hasValue ?Newvalue}"});


request.post('http://localhost:3030/DS-1/sparql?'+myquery, function (error, response, body) {
  if (!error && response.statusCode == 200) {
   // Show the HTML for the Google homepage.
console.log('successful update');
console.log(body);

  } else {
   console.log(response.statusCode);
   console.warn(error);
  }
});

PS: When I use POSTMAN to send the Post request to insert data it works fine but from my node app, it doesn't. it shows error 'bad request 400'. P.S: GET methods work fine from both POSTMAN and node app.

via Usman Khan