Double-check your API keys were pasted correctly with no extra whitespace, and confirm you're using live (production) keys rather than test/sandbox keys if you're expecting real payments to process. A single mismatched character in a secret key is the most common cause of an immediate failure.

This almost always points to a webhook misconfiguration. Go back to your gateway's dashboard and confirm the webhook URL and secret exactly match what Koursely's integration settings page provided — a missing or incorrectly configured webhook means Koursely never receives confirmation that the payment succeeded, even though the gateway itself processed it correctly.

Confirm UPI is actually enabled on your gateway account — some gateway accounts require UPI to be activated separately from card processing during onboarding, especially for newly created merchant accounts.

This is a gateway-side KYC or compliance hold, not a Koursely issue — check your gateway's own dashboard for pending verification requirements (business documents, bank account confirmation) and resolve those directly with the gateway's support team.

Confirm the coupon hasn't expired or hit its maximum redemption count, and that it's scoped to include the specific course or service being purchased — a coupon scoped to one course won't apply to a different one by default.