Image based, detailed installation steps inside of archive.

Unpack downloaded google_captcha_v3_for_oc4.zip file.

Archive google_captcha.ocmod.zip is your extension.

Folder captcha-images contains 20 images containing 20 easy steps how to install this module.
Steps 12 to 15 show how to get captcha keys: site (public) and secret.
Just follow these steps and you are done.

For free.
You are welcome.
;)

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Update: 2024.08.22-15:08

There was a small error in admin/controller file.
As a result keys you updated/entered anew were not showing after you came back to admin page again.
They were being added to database, just not fetched at page refresh.
Corrected.

Admin page for Captcha 3 keys entry I mentioned can be found at:


A new version uploaded: google_captcha_v3_for_oc4_v1.1

If you have installed older version, just go to this file in your code:
public\extension\google_captcha\admin\controller\captcha\google.php
... and add these two lines:
$data['captcha_google_key'] = $this->config->get('captcha_google_key');
$data['captcha_google_secret'] = $this->config->get('captcha_google_secret');
... after this line (ca. code line #40):
$data['captcha_google_status'] = $this->config->get('captcha_google_status');

If you wish to see, if keys were added to your database:
1. go to table: settings
2. find in column 'key' these keys:
- captcha_google_key
- captcha_google_secret
... and see if you can find your keys in corresponding column 'value'.

Any more problems, report them please and will try to address them as time allows.