I’m assuming this means adjusting a user’s group memberships on a particular Discourse site when they make a purchase on the WordPress site. That sounds doable, but would best be done with an API request to the sync_sso route. The WP Discourse plugin has functions that can be used for this, but they use the Discourse URL and API Key that’s set on the plugin’s options pages: https://github.com/discourse/wp-discourse/blob/main/lib/utilities.php#L278-L326. Maybe the plugin could add filter hooks to those params so that they can be set conditionally.