google recaptcha in cakephp

For google recaptcha at first register your site at this link: https://www.google.com/recaptcha/admin

Enter your site details. if you have to use on local machine then enter domain name and lable as 'localhost'.
In controller

    function recaptcha(){
    if(isset($_POST['submit'])){
        if(isset($_POST['g-recaptcha-response']) && !empty($_POST['g-recaptcha-response'])){
            //your site secret key
            $secret = '6LfR2xMUAAAAAJ9EvvLrA5mQUqZ77owaFQ3RVvou';
            //get verify response data
            $verifyResponse = file_get_contents('https://www.google.com/recaptcha/api/siteverify?secret='.$secret.'&response='.$_POST['g-recaptcha-response']);
            $responseData = json_decode($verifyResponse);
         
            $name = !empty($_POST['name'])?$_POST['name']:'';
            $email = !empty($_POST['email'])?$_POST['email']:'';
            $message = !empty($_POST['message'])?$_POST['message']:'';
            if($responseData->success){
                //contact form submission code
                $to = 'gautam8953@gmail.com';
                $subject = 'New contact form have been submitted';
                $htmlContent = "
                    <h1>Contact request details</h1>
                    <p><b>Name: </b>".$name."</p>
                    <p><b>Email: </b>".$email."</p>
                    <p><b>Message: </b>".$message."</p>
                ";
                // Always set content-type when sending HTML email
                $headers = "MIME-Version: 1.0" . "\r\n";
                $headers .= "Content-type:text/html;charset=UTF-8" . "\r\n";
                // More headers
                $headers .= 'From:'.$name.' <'.$email.'>' . "\r\n";
                //send email

                @mail($to,$subject,$htmlContent,$headers);
             
                $succMsg = 'Your contact request have submitted successfully.';
                $name = '';
                $email = '';
                $message = '';
                $errMsg = '';
            }else{
                $errMsg = 'Robot verification failed, please try again.';
                $succMsg = '';
                $this->set('name',$name);
                $this->set('email',$email);
                $this->set('message',$message);
            }
        }else{
            $errMsg = 'Please click on the reCAPTCHA box.';
            $succMsg = '';
            $this->set('name',$name);
            $this->set('email',$email);
            $this->set('message',$message);
        }
    }else{
        $errMsg = '';
        $succMsg = '';
        $name = '';
        $email = '';
        $message = '';
    }
    $this->set('errMsg',$errMsg);
    $this->set('succMsg',$succMsg);
    }

in view recaptcha.ctp
<script src="https://www.google.com/recaptcha/api.js" async defer></script>

    <div class="registration">
<h2>Contact Form</h2>
        <?php if(!empty($errMsg)): ?><div class="errMsg"><?php echo $errMsg; ?></div><?php endif; ?>
        <?php if(!empty($succMsg)): ?><div class="succMsg"><?php echo $succMsg; ?></div><?php endif; ?>
<div class="form-info">
<form action="" method="POST">
<input type="text" class="text" value="<?php echo !empty($name)?$name:''; ?>" placeholder="Your full name" name="name" >
                <input type="text" class="text" value="<?php echo !empty($email)?$email:''; ?>" placeholder="Email adress" name="email" >
                <textarea type="text" placeholder="Message..." required="" name="message"><?php echo !empty($message)?$message:''; ?></textarea>
<div class="g-recaptcha" data-sitekey="6LfR2xMUAAAAABBy2TBrBKur0_L23TizUGR-M20s"></div>
<input type="submit" name="submit" value="SUBMIT">
</form>
</div>
<div class="clear"> </div>
</div>