The first step would be to find the needed section where you can set the redirect URL. Login to your Chargebee and navigate to Product Catalog> Plans and edit each plan you want to integrate. Each plan has its own redirect URL, just make sure to use these params in it:
Put the following code into the redirect URL you defined in each plan:
Chargebee gives us an option to use webhooks which we can use to track recurring commissions. To setup a webhook, first enable the Chargebee plugin in your merchant panel. Then navigate to your Chargebee account into Settings> Configure Chargebee and find section 'API keys and webhooks' Enter the section and then navigate to Webhooks. Add a new webhook using the button there. USe the following URL for the webhook:
https://URL_TO_PostAffiliatePro/plugins/Chargebee/chargebee.php - save it and you are done.