express use post to add items to json code example
Example: 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);