Use reCAPTCHA 2.0
It is ready to use in your plugins already.
First sign up and get keys. https://www.google.com/recaptcha/admin
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.
April 20, 2021: Q2A 1.8.6 released!