Google-reCaptcha-V3 You can learn how to use reCaptcha v3 on your website. Using curl to send a request. File in each side : Client side : frontEnd.html, frontEnd.js Server side : backEnd.php You can get your own recaptcha key by this link. If it runs successfully, there will be a icon on the bottom right of the page. Like https://www.google.com/recaptcha/intro/v3.html.