So all of those lines are doing nothing… If i cut out all of the unused lines, your code is currently this:
$mail = new PHPMailer();
$mail->isSMTP();
$mail->SMTPSecure = PHPMailer::ENCRYPTION_SMTPS; //This is equivalent to "ssl". If you're expecting TLS, this should be ENCRYPTION_STARTTLS
$mail->SMTPAuth = 'PLAIN'; // Not valid, should be a boolean.
$mail->isHTML(true); //true, but message doesnt contain HTML.
$mail->SMTPDebug = 3; //Showing all messages from both sides.
$mail->setFrom('nasratullahkhadim00@gmail.com', 'Nasratullah Khadim');
$mail->addAddress($email);
$mail->Subject = 'This is a test email';
$mail->Body = 'Email body';