onOrderRequest
Only applicable for partial payments flow.
In this method you should make a network call to the /orders endpoint of the Checkout API through your server. This method is called when the user is trying to pay a part of the Drop-in amount using a partial payment method.
NOTICE: this method runs on the main thread, you should make sure the API call and any other long running operation is made on a background thread.
You should eventually call sendOrderResult with a OrderDropInServiceResult containing the result of the network request. The base class will handle messaging the UI afterwards, based on the OrderDropInServiceResult.
Note that not overriding this method while enabling partial payments will cause a MethodNotImplementedException to be thrown.
See https://docs.adyen.com/api-explorer/ for more information on the API documentation.