Google reCAPTCHA is a free service to protect your website from spam and abuse. This addon allows you to add captcha to your affiliate signup page. This will prevent spam bot signups (if any).
In order to add Google reCAPTCHA verification option to your affiliate registration form, simply follow these steps:
Step 1 (Install the Plugin)
Download and Install the Affiliates Manager Google reCAPTCHA Integration addon
Step 2 (Go to Settings Interface)
Click on the “Google reCAPTCHA” menu from the Affiliates Manager plugin’s admin interface.

Step 3 (Specify Google reCAPTCHA API Credentials)
Enter your Google reCAPTCHA Site key and Secret key.
You can create Google reCAPTCHA keys from Google’s reCAPCHA site.
Create V2 reCAPTCHA API Keys. The following screenshot shows an example:

After you create the API keys, you can enter them in the reCAPTCHA addon’s settings interface. Example screenshot below:

Click Save to save the options.
When your affiliates go to the registration page, they will need to manually confirm that they are not a robot before submitting the form.