谷歌reCAPTCHA错误如何停止？

Question

我试图让谷歌验证码工作，但它不会，它总是失败说“错误的验证码请再试一次！”。谁能看到我是否在任何地方做错了什么？

PHP

 if(isset($_POST)){     
        $captcha=$_POST['g-recaptcha-response'];
        $ip = $_SERVER['REMOTE_ADDR'];
        $secretkey = "4444444444444444444444444444";                    
        $response=file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=".$secretkey."&response=".$captcha."&remoteip=".$ip);
        $responseKeys = json_decode($response,true);         
    
        if(intval($responseKeys["success"]) !== 1) {
            echo '<h2>Wrong captcha try again please!</h2>';
            exit;
        } else {
            echo '<h2>Success!</h2>';   
            exit;       
        }                   
    }

HTML

     <form id="regerform" method="post" action="register.php" class="form">
            <div class="third">

            <div class="thirdLast">
                <label for="username">
                    <?php echo t("username", "username"); ?>:
                </label>
                <input type="text" tabindex="3" value="<?php echo isset($username) ? safeOutputToScreen($username) : ''; ?>" id="username" name="username">
            </div>
            <div class="clear"></div>
           
            <div class="g-recaptcha" data-sitekey="4444444444444444444444444444"></div>
            
 </form>