Quote Originally Posted by jeking View Post
From the instructions:

Installation for Zen Cart version v1.5.5/v1.5.6
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Step 3
Since the responsive_classic files are new to v1.5.5 there are modified copies of those files included in the v155-only folder.
Also, since the template_default files in v1.5.5 were changed a lot to modernize how error messages and HTML field types are presented, the v155-only folder also contains "classic" template files, which are basically the template_default equivalents for v1.5.5.

NOTE: In all these cases, the ONLY change relevant to this plugin is that the following line has been added to the form in each of these template files. You could easily add it yourself wherever you wish the Recaptcha box to display:

<?php echo recaptcha_get_html(); ?>

If you've uploaded files into the template_default folder, that will not matter and no cause the error you see.

Do you have this in place correctly?
/includes/functions/extra_functions/recaptchalib.php

$publickey is what Google calls the Site Key
privatekey is the Secret Key

When you created your reCAPTCHA key, did you select v2 Checkbox?
I will check, however, I have followed your instructions to the letter. What I will have to is hard copy them remove this plugin and start again. With reCAPTCHA key, I only had v3 as an option, does this matter? or is this the problem not using v2?