Simple page</title> <script src="https://www.google.com/recaptcha/api.js" async defer></script> <script> function onSubmit(token) { document.getElementById("demo-form").submit(); } function onClick() { // όϦσʔγϣϯΛߦ͏ grecaptcha.execute(); } </script> </head> <body> <form id='demo-form' action="?" method="POST"> <div class="g-recaptcha" data-sitekey="your_site_key" data-callback="onSubmit" data-size="invisible"> </div> <button onClick="onClick" /> </form> </body> </html>