CODE EXAMPLE FOR JAVASCRIPT

node express post request json

var express = require('express');

var app = express();

app.use(express.json()); // built-in middleware for express

app.post('/', function(request, response){
 	let myJson = request.body;      // your JSON
	let myValue = request.body.myKey;	// a value from your JSON
	response.send(myJson);	 // echo the result back
});

app.listen(3000);