To make a captcha working on your website, you have to get your own Site Key and Secret Key.
1) Log in to your Google reCaptcha Admin Console via the following link https://www.google.com/recaptcha/intro/v3.html
2) Click on plus sign to create and register a new site
3) It’s important to select “reCAPTCHA v3” type while you are registering your site on the “Register new site” page and fill in your domain name where captcha will be used
4) Keys are generated after submit, simply copy and paste keys to appropriate inputs in Listing Settings