Code to test how to use Keygen transformations.

keygen-transformations-test.php

<?php

require __DIR__ . '/vendor/autoload.php';
use Keygen\Keygen;

$splitString = function($key) {
    return join('-', str_split($key, 4));
};

$shortHash20 = function($key) {
    return substr(md5($key), mt_rand(0,8), 20);
};

$reference = Keygen::numeric(20)->generate($splitString);

$filename = Keygen::bytes()->suffix('.png')->generate(true, ['strrev', $shortHash20], 'strtoupper');

echo $reference; // 2129-1489-0676-5152-9337
echo $filename; // 159D702E346F74E3F0B6.png