Fatal error in Library 'require' and 'use' PHP - php

Question

I'm trying to implement https://github.com/zytzagoo/smtp-validate-email for email validation, but I have a problem in the sintallation of the package (manually, I'm not using composer)
So here is the hierarchy of my files:
My index has this code:
<?php
require 'Library/Validator.php';
use \Library\Validator;
$email = 'someone#example.org';
$sender = 'sender#example.org';
$validator = new Validator($email, $sender);
$results = $validator->validate();
var_dump($results);
$log = $validator->getLog();
var_dump($log);
?>
And the 'Validator.php' has 1000 lines of code but here are the first 25 lines so you can have an idea:
<?php
namespace SMTPValidateEmail;
use \SMTPValidateEmail\Exceptions\Exception as Exception;
use \SMTPValidateEmail\Exceptions\Timeout as TimeoutException;
use \SMTPValidateEmail\Exceptions\NoTimeout as NoTimeoutException;
use \SMTPValidateEmail\Exceptions\NoConnection as NoConnectionException;
use \SMTPValidateEmail\Exceptions\UnexpectedResponse as UnexpectedResponseException;
use \SMTPValidateEmail\Exceptions\NoHelo as NoHeloException;
use \SMTPValidateEmail\Exceptions\NoMailFrom as NoMailFromException;
use \SMTPValidateEmail\Exceptions\NoResponse as NoResponseException;
use \SMTPValidateEmail\Exceptions\SendFailed as SendFailedException;
class Validator
{
public $log = [];
/**
* Print stuff as it happens or not
*
* #var bool
*/
public $debug = false;
So, the output of the 'index.php' is this:
Fatal error: Uncaught Error: Class "Library\Validator" not found in C:\xampp\htdocs\EmailValidation\index.php:9 Stack trace: #0 {main} thrown in C:\xampp\htdocs\EmailValidation\index.php on line 9

Answer 1

use namespace name and class name to call it.
use \SMTPValidateEmail\Validator;
example
namespace Helpers
and the CheckUser class
then the text becomes
use Helpers/CheckUser;