Node.js mass account naming script

"use strict";
var request = require('request'); //The module to make calls to ROTMG server, please run 'npm install request' first.
const baseUrl = 'http://realmofthemadgod.appspot.com/';
var accNames = {},
letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
number = '0123456789';
function namer(email, pass) { //the function to namne accounts
    var name = `Tom${randomValue(6, letters)}`; //you can change Tom to whatever, but beware that there is a limit on name length so I'd keep it at a 3 letter word + the random letters
    var info = {
        guid: email,
        ignore: randomValue(4, number),
        password: pass,
        name: name
    }
    var accUrl = buildUrl(baseUrl + 'account/setName', info);
    request(accUrl.substring(1, accUrl.length - 1), (error, response, body) => {
        if (!error && response.statusCode == 200) {
            accNames[email] = pass;
            console.log(`Account named! Email: ${email}, name: ${name}`);
        } else {
            console.log(`${error}\n${body}`);
        }
    })
}

function randomValue(len, charSet) { //random shit, move along
    var randomString = '';
    for (var i = 0; i < len; i++) {
        var randomPoz = Math.floor(Math.random() * charSet.length);
        randomString += charSet.substring(randomPoz, randomPoz + 1);
    }
    return randomString;
}

function buildUrl(url, parameters) { //build the url with all the information we need to send to ROTMG in order to name the mule
    var qs = "";
    for (var key in parameters) {
        var value = parameters[key];
        qs += encodeURIComponent(key) + "=" + encodeURIComponent(value) + "&";
    }
    if (qs.length > 0) {
        qs = qs.substring(0, qs.length - 1);
        url = url + "?" + qs;
    }
    return JSON.stringify(url);
}

var accountsList = { //put your accounts here, in muledump format.
    "email+0@gmail.com": "password",
    "email+1@gmail.com": "password",
    "email+2@gmail.com": "password"
};

var listArray = Object.keys(accountsList);
(()=>{
    listArray.forEach((item, index) => {
        namer(item, accountsList[item]);
    })
})();