1. Go to this page and download the library: Download arkecosystem/fortify library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
return [
// ...
'username_alt' => 'username',
// Or set that setting to `null` so the user can only login/register with email:
// 'username_alt' => null,
// ...
];