It does work with 2.

The error indicates a problem with steps 1 and 2.

Step 1
Go to https://www.google.com/recaptcha/admin and create the Google reCAPTCHA keys for your website
Step 2
Open the file /includes/functions/extra_functions/recaptchalib.php and insert the public and private keys you got in Step 1. They need to go on lines 9 and 10

Quote Originally Posted by Goshawk View Post
I have installed your latest plugin (19 Dec 2018) on my zen-cart 1.5.5f.
I get the following message: ERROR for site owner: Invalid site key
I have completed the set up as instructed and put the keys in the correct file.

Does this plugin only work with reCAPTCHA 2?

Thanks,

Goshawk