How can I change variable value from console in a file on a website

I am on a website, and on this website there is a file named "Away.js". Which starts:

var S = require('core/Storage');
var I = require('core/InputParser');
module.exports = function () { var tAfk;

And everything else is in the function(). I need somehow to change the value of tAfk, is that even possible?

via Josh