WPForms Form CAPTCHA

the recaptcha option is not displayed

For me it doesn't show up ever. In the instructions it says "That’s it! You can now add reCAPTCHA to any of your forms for added spam protection." - But it never says how to actually add it. Neither does this video.
EDIT: I had a look at the source code, and the reCaptcha is actually there. Would be great to have some kind of confirmation that it is actually active.

Did it right but the CAPTCHA doesn't show up until AFTER you have clicked the submit button, in FireFox. Forcing the submitter to type in everything again.