API Error: /v1/invoices/:id/payment-currencies/:currency returns 404 "Payment not found"

[420-Bits]

Dear CoinPayments Support,

I'm encountering an issue when calling the following API endpoint:

GET /v1/invoices/:id/payment-currencies/:currency

Despite successfully creating an invoice via the /v2/merchant/invoices endpoint, when I attempt to retrieve payment currency details for that invoice, the following response is returned:

{
    "type": "https://api.coinpayments.net/problems/not-found",
    "title": "Not Found",
    "status": 404,
    "detail": "Payment not found"
}

Details:
The invoice ID used is obtained directly from the response of the invoice creation API.
The currency ID is valid and listed under the payment.paymentCurrencies of the invoice response.
The error occurs consistently for all test currencies, even when using a known working currency like LTCT.

Questions:
Are there any delays or additional steps required before the /payment-currencies/:currency endpoint becomes available?

Please advise on whether I’m missing a required step or if there’s an issue on your side. I’m happy to provide full request/response logs if needed.

Thank you.

[420-Bits]

It appears that the payment.refundEmail field is mandatory when creating an invoice, even though this requirement is not documented in the official API reference:
https://docs.coinpayments.net/#operation/createInvoiceV2

Please update the documentation to reflect this requirement or clarify if this behavior is unintended.