Once I add the captcha (v2, I'm not a robot one) it does add message "Enter captcha" on the wiki, but its invisible and you can't click on it, therefore its impossible to do anything.
Topic on Extension talk:ConfirmEdit
Look at the browser console to see what happens, i.e. if errors are shown. It may e.g. be that a Content Security Policy (CSP) is enabled for the wiki that prevents the NoCaptcha code from being loaded. Happened to me once.