서버 측에서 Google reCAPTCHA v3의 유효성을 어떻게 확인합니까?

<code class="php">function isValid() {
    try {
        $url = 'https://www.google.com/recaptcha/api/siteverify';
        $data = [
            'secret'   => '[YOUR SECRET KEY]',
            'response' => $_POST['g-recaptcha-response'],
            'remoteip' => $_SERVER['REMOTE_ADDR']
        ];
        $options = [
            'http' => [
                'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
                'method'  => 'POST',
                'content' => http_build_query($data)
            ]
        ];
        $context  = stream_context_create($options);
        $result = file_get_contents($url, false, $context);
        return json_decode($result)->success;
    } catch (Exception $e) {
        return null;
    }
}</code>

<code class="php">if (isValid()) {
    // The user has passed the reCAPTCHA check.
    // ...
} else {
    // The user has failed the reCAPTCHA check.
    // ...
}</code>