How to add reCAPTCHA (v3) for Contact Form 7 plugin in WordPress
Important Note: reCAPTCHA (v3) doesn’t need a CAPTCHA widget (the “I’m not a robot” checkbox used in reCAPTCHA v2) to work, so [recaptcha] form-tags are no longer necessary. If [recaptcha] form-tags are found in a form template, Contact Form 7 5.1 or higher ignores them and replaces them with an empty string. Introduction reCAPTCHA