Here we are assuming that you already have bought SiteSEO Pro and have a license key with you, if you haven't done that please check guide for How to buy SiteSEO Pro.
The SiteSEO Pro Plugin is available for download from the Client area after you have purchased your license.
Note: You can download the plugin as long as your license is active. Once your license expires you will need to renew your license to download the latest package.
The following is a screenshot of the Client area showing the download link :
Linking License with the Plugin
After installation, you just need to link the license with the Plugin and then you will be able to get updates.
Add my license key to wp-config.php
This is the second way to link your License with SiteSEO, for that you will need to define the license constant in wp-config.php file.
define('SITESEO_LICENSE_KEY', 'YOUR_LICENSE_KEY');
Make sure you update your license key here, and then save the wp-config.php and then the license will be activated.
If you face any issue in any step, you can reach out to our support team, they will help you out, you can contact us at support@siteseo.io