Tab: Business > Integrations. Options: v2 - Checkbox (I'm not a robot) (default) or v3 - Invisible (score based). Global only.

It must match the type of reCAPTCHA keys you created in the Google reCAPTCHA admin console and entered on the Integrations page. With v2 your forms show the I'm not a robot checkbox; with v3 the check is invisible and score-based. Choosing a version that does not match your keys makes form submissions fail the captcha check.