我正在使用php联系表单和Google reCAPTCHA通过电子邮件发送表单数据

但它不起作用

我正在使用Google reCAPTCHA版本2

这是html代码

 
<?php

if (isset($_POST['g-recaptcha-response'])) {
  $captcha = $_POST['g-recaptcha-response'];
}

if (!$captcha) {
  echo 'Please check the the captcha form.';
  exit;
}

$secret = '6LdP61AkAAAAAKmCUXdCbJEKGwwbHhqyLGd2jsMW';
$response = file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=" . $secret . "&response=" . $captcha . "&remoteip=" . $_SERVER['REMOTE_ADDR']);
$response = json_decode($response);

if ($response->success === false) {
  echo 'You are a spammer!';
} else {
  echo 'Thanks for posting comment.';
  
  // Prepare email content
  $to = "nextr2020@gmail.com";
  $subject = "Contact form submission";
  $message = "Name: " . $_POST['name'] . "\n";
  $message .= "Email: " . $_POST['email'] . "\n";
  $message .= "Message: " . $_POST['message'];
  
  // Send email
  $header = "From: nextr2020@gmail.com\r\n";
  if (mail($to, $subject, $message, $header)) {
    echo "Your email has been sent successfully.";
  } else {
    echo "Failed to send email. Please try again later.";
  }
}

?>

我正在使用php