How to press a key using nodejs?

I would like to know how to get a certain key on the keyboard to be pressed via code on nodejs.

For instance, I want the f3 button to pressed once the following page is rendered:

var express = require('express');
var router = express.Router();


/* GET home page. */
router.get('/', function(req, res, next) {
   // press key
});

module.exports = router;

via John