CM Anonymous User Posting - reCAPTCHA Support
Protecting from Spam - Human verification with reCaptcha
reCAPTCHA V2 Only
This add-on doesn't support reCAPTCHA V3.
The Anonymous User Posting Add-on comes with reCAPTCHA support (V2 only).
This means you can keep your website spam-free! You can find the URLs to acquire captchas and choose your reCAPTCHA settings under the Anonymous Posting tab in the plugin settings.
You need to acquire your API keys for reCAPTCHA service from Google and enter them into the plugin settings before the reCAPTCHA box will work. After entering the API keys, an anonymous user will be prompted to fill in the reCAPTCHA when they attempt to post on your Q&A forum.