Recaptcha with custom action in form

We need a recaptcha on our company website for our sign up form because many bot registrations come in. Unfortunately the recaptcha of webflow does not work with a custom action. Has anyone found a way to do this?
I had the idea to take the detour with zapier, but in the webflow forms no passwords can be sent…

Here is my site Read-Only: LINK
(how to share your site Read-Only link)