Configure Chargebee dunning settings and handle the payment_failed webhook to implement a custom retry sequence

Steps

1. In Chargebee settings, configure a dunning schedule under Retry Settings with desired intervals and maximum attempts
2. Set up a webhook endpoint in Chargebee and subscribe to the payment_failed event
3. On webhook receipt, retrieve the Invoice object via GET /api/v2/invoices/:id and inspect its dunning_status and next_retry_at fields
4. If business logic requires an out-of-band retry, call POST /api/v2/invoices/:id/collect_payment to trigger an immediate charge attempt
5. After exhausting retries, the invoice moves to not_paid status and the subscription may become cancelled; listen for subscription_cancelled events and trigger a win-back flow