I’m not sure from your earlier message whether your have made your own changes to enable ReCAPTCHA v2, or if you have use the changes pending for OJS 2.4.9 in GitHub. What specifically did you do with respect to the code?
Edit: I see now that you are probably using OJS 3.x. Since this thread started out discussing adding ReCAPTCHA v2 to OJS 2.4.x, your problem might be better discussed on a different thread. I see you have also posted this question here: