How to send emails using PHPMailer in php (code attached)

<?php

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

require &#39;./PHPMailer/src/Exception.php&#39;;
require &#39;./PHPMailer/src/PHPMailer.php&#39;;
require &#39;./PHPMailer/src/SMTP.php&#39;;


$mail = new PHPMailer(true);                              // Passing `true` enables exceptions
try {
    //Server settings
    $mail->SMTPDebug = 2;                                 // Enable verbose debug output
    $mail->isSMTP();                                      // Set mailer to use SMTP
    $mail->Host = &#39;smtp.qq.com&#39;;  							// Specify main and backup SMTP servers
    $mail->SMTPAuth = true;                               // Enable SMTP authentication
    $mail->Username = &#39;xxx@qq.com&#39;;                 // SMTP username
    $mail->Password = &#39;xxxx&#39;;                           // SMTP password  QQ邮箱授权码
    $mail->SMTPSecure = &#39;tls&#39;;                            // Enable TLS encryption, `ssl` also accepted
    $mail->Port = 587;                                    // TCP port to connect to

    //Recipients
    $mail->setFrom(&#39;xxx@qq.com&#39;, &#39;Mailer&#39;);
    $mail->addAddress(&#39;xxx@qq.com&#39;, &#39;Joe User&#39;);     // Add a recipient
    $mail->addAddress(&#39;xxx@qq.com&#39;);               // Name is optional
    $mail->addReplyTo(&#39;xxx@qq.com&#39;, &#39;Information&#39;);
    $mail->addCC(&#39;xxx@qq.com&#39;);
    $mail->addBCC(&#39;xxx@qq.com&#39;);

    //Attachments
    //$mail->addAttachment(&#39;/var/tmp/file.tar.gz&#39;);         // Add attachments
    //$mail->addAttachment(&#39;/tmp/image.jpg&#39;, &#39;new.jpg&#39;);    // Optional name

    //Content
    $mail->isHTML(true);                                  // Set email format to HTML
    $mail->Subject = &#39;Email title&#39;;
    $mail->Body    = &#39;Email body&#39;;
    $mail->AltBody = &#39;This is the body in plain text for non-HTML mail clients&#39;;

    $mail->send();
    echo &#39;Message has been sent&#39;;
} catch (Exception $e) {
    echo &#39;Message could not be sent. Mailer Error: &#39;, $mail->ErrorInfo;
}