[field troubleshooting guide]: The two usual causes are the webhook endpoint URL not being registered in the Finix dashboard, or the webhook credentials in the app not matching the dashboard values exactly. Finix cannot deliver webhooks to YOUR_HOST or a private network, so the endpoint must be publicly reachable over HTTPS. Enable debug logging, run a test payment, and check the logs for webhook delivery errors to tell a registration problem from a credential mismatch.

Context: Finix payments succeed at the gateway but orders stay stuck in pending because the Finix webhooks are never received.