When the client goes to checkout, the client-server sends a create cart request to Digital River and Digital River returns the cart. The client-server then sends a request to provide the payment session ID to the client's front end. The client front end instantiates Drop-in with the payment session ID and configurations, and Drop-in displays the payment methods. When the customer selects a payment method and provides their payment details, the client front end triggers an
onSuccess event and sends the source ID to the client-server. The client-server uses the source with the cart or shopper.