Hi,
You have to add some settings to your wp-config.php file:
define( 'CONTENT_STAGING_SECRET_KEY', 'YOUR_GENERATED_KEY' );
define( 'CONTENT_STAGING_ENDPOINT', 'https://YOUR_PRODUCTION_SITE.com' );
define( 'CONTENT_STAGING_TRANSFER_TIMEOUT', 60 );
Make sure to add these settings somewhere before:
require_once(ABSPATH . 'wp-settings.php');
For more information about the installation, see https://www.ads-software.com/plugins/content-staging/installation/
Hope that helps!