Payment with a New Card (3‑D Secure)
This flow adds 3‑D Secure protection to ensure extra security. You’ll need three integration points:

Initialize 3‑D Secure
Call POST /moneyins/card/direct/3dinit.
- You’ll receive an Authentication URL and a Transaction Id.
- To save the card for future one‑click or subscription payments, include registerCard=true.
Redirect to ACS
Send the end‑user’s browser to the Authentication URL so they can complete 3‑D Secure authentication on their bank’s ACS (Access Control Server) page.
Handle the Return Callback
After authentication, the ACS will redirect back to your configured ReturnURL.
Verify Authentication
Call
```
POST /moneyins/card/direct/{transactionId}/3dauthenticate
```
to confirm that the user passed 3‑D Secure checks.
Confirm the Payment
If authentication succeeded, finalize the charge by calling
```
PUT /moneyins/card/direct/{transactionId}/3dconfirm
```
using the same Transaction Id.

Payment with a Registered Card
Once you have a cardId saved, you can skip the initial registration step:

Initialize with Card ID
Call POST /moneyins/card/direct/3dinit and include:
- cardId (required)
- cvv (optional—adding it can improve authorization rates)
Follow Steps 2–5 Above
- Redirect the user to the ACS using the returned Authentication URL.
- Handle the ReturnURL callback.
- Call 3dauthenticate, then 3dconfirm.

Note: You only receive the cardId after your very first 3‑D Secure payment is confirmed via PUT /moneyins/card/direct/{transactionId}/3dconfirm. To double-check that a saved card is valid before charging it, you can call GetCard.

Subscription Payments
Prerequisite: You must already have a registered card (from your initial 3‑D Secure payment via POST /moneyins/card/direct/3dinit).

Amount Requirements: Ensure recurringAvgAmount is greater than totalAmount. Otherwise you’ll get error 368 (recurringAvgAmount should be greater than the transaction amount).
Setup Endpoint: Once the card is registered, start subscriptions by calling:
```
POST /moneyins/card/{cardId}/rebill
```

Important: For the smoothest, most “frictionless” experience, use the same amount for each recurring payment.