MailBluster Form uses Google reCaptcha V3, which does not display a checkbox to confirm human interaction. Instead, it uses an advanced risk analysis engine and adaptive challenges to keep malicious software from engaging in abusive activities on your website. So, it will never display a checkbox, but it won’t compromise either.
You can place the Google Recaptcha checkbox protection from the Forms > Edit form page.

Learn more about Google Recaptcha V3 from here: https://developers.google.com/recaptcha/docs/v3