Set applying captcha anywhere in form google captcha.

 add_action( 'wp_login_failed', 'pippin_login_fail' );  // hook failed login

function pippin_login_fail( $username ) {
      
        global $wbdb;
   
     $userdata = get_user_by( 'login', $username );
   
     $meta = get_user_meta($userdata->ID, 'theme_my_login_security', true );
  
   if ( ! is_array( $meta ) )
           $meta = array();
   
    if(sizeof($meta['failed_login_attempts'] ) > 1){
       
       
    ?>
         <script src="https://www.google.com/recaptcha/api.js" async defer></script>
           <script type="text/javascript">
            jQuery('.g-recaptcha').show();

           </script>
    <?php
         
    }

   
}
add_filter('wp_authenticate_user', 'verify_login_captcha', 10, 2);
       
function verify_login_captcha($user, $password) {

    if (isset($_POST['g-recaptcha-response'])) {
        $recaptcha_secret = '6LfkBpNteuL6rHOViv9';
        echo $_POST['g-recaptcha-response'];
        echo "<br/>";
        $response = wp_remote_get("https://www.google.com/recaptcha/api/siteverify?secret=". $recaptcha_secret ."&response=". $_POST['g-recaptcha-response']);
        print_r($response);
        $response = json_decode($response["body"], true);
       
       
       
       
        if (true == $response["success"]) {
            return $user;
        } else {
            return new WP_Error("Captcha Invalid", __("You are required to check security verification"));
        }
       
    } else {
       
        return $user;
        //return new WP_Error("Captcha Invalid", __("<strong>ERROR</strong>: You are a bot. If not then enable JavaScript"));
    }  
}
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 <div class="clear"></div>
        <div class="g-recaptcha" data-sitekey="6LfkKwoTAAA1r7mO3d67rZnJu3"></div>