# Checkout SDK Invoice Flows

This guide covers invoice behavior for the "Pay Now" flow in Checkout SDK integrations.

## Invoices from "Pay Now" flow

After a successful checkout, a DUR invoice is created. This invoice will show up in the merchant's dashboard, and will be available in the buyer's dashboard once captured.

The customer is redirected to your `success_url` with the `merchant_invoice_id` appended:


```
https://www.merchantsite.com/confirm?merchant_invoice_id=czTrT9opfkBaYZNh
```

On your success page:

1. Redirect the customer to the order confirmation page or display an order confirmation message.
2. Store the `merchant_invoice_id` in your order management system, since it will be used to capture the invoice.
3. Mark the order payment as pending.


## Invoice capture

To send the invoice to the customer, capture the invoice using `merchant_invoice_id`.

| Environment | Endpoint |
|  --- | --- |
| Production | `POST` `https://app.resolvepay.com/api/invoices/<merchant_invoice_id>/capture` |
| Sandbox | `POST` `https://app-sandbox.resolvepay.com/api/invoices/<merchant_invoice_id>/capture` |


Use either HTTP Basic Auth (`merchant_id` + `secret_key`) or Bearer token auth.

**Success response:**


```json
{
  "id": "S189qSj9f",
  "number": "R334-66S9",
  "order_number": "ORDER NUMBER",
  "amount_due": 74.97,
  "sent_at": "2018-03-30T17:54:08.329Z",
  "created_at": "2018-03-30T05:26:38.517Z",
  "updated_at": "2018-03-30T17:54:08.330Z"
}
```

## Related guide

- [Checkout SDK](/guides/checkout-sdk)