Follow these steps to perform a payment using Nuvei Web SDK integration.

1. Initiate a Session

Before you can submit payment using the client-side Nuvei Web SDK, you need to send the /openOrder API call.

2. Initialize the Web SDK

Instantiate the Web SDK with the sessionToken received from the server call to /openOrder.

3. Retrieve a list of UPOs

Once the customer selects the payment method, call /getUserUPOs request to retrieve a list of the customer’s UPOs.
(If no appropriate UPOs are returned, then skip the rest of these steps, and perform the steps in the Payment (without UPO) flow instead.)

4. Offer UPO(s) to customer

Offer the “returning customer” the option to select one of their previously captured payment methods (stored in a UPO record, userPaymentOptionId, representing the customer’s bank account), instead of collecting their bank account details again.

• If the customer selects one of their UPOs, then continue with the next step.
• If not, then skip the rest of these steps, and perform the steps in the Payment (without UPO) flow instead.

5. Create an APM Payment

Send a createPayment() request with its mandatory parameters including: