1)An app that requires a customer pay only once for all features

  After authentication, you will get the customer's customerId and token from our backend. When the customer starts to pay, Create Order by the following param values:
bizNo=CONCAT(customerId, "Default")(or whatever fixed string you like)
customerIdentity=customerId.
  When the customer has logged onto another device, Query Order by the above param values again, you will get to know whether the customer has paid or not.


2)An app that requires a customer to pay several times for fixed levels of service such as VIP1、VIP2、VIP3、VIP2019、VIP2020

  After authentication, you will get the customer's customerId and token from our backend. When the customer starts to pay, Create Order by the following param values:
bizNo=CONCAT(customerId, (one of)VIP1、VIP2、VIP3、VIP2019、VIP2020)
customerIdentity=customerId.
  When the customer has logged onto another device, Query Order by the above param values again, you will get to know whether the customer has paid for a service or not.


3)An app that requires a customer to pay for many separate products/orders

  In this condition, you probably have your own backend server, use your own Customer Management System and Order Management System.
  When the customer starts to pay, Create Order by the following param values:
bizNo=your backend orderId
customerIdentity=your backend customerId
  When the customer has logged onto another device, Query Order by the above param values again, you will get to know whether the customer has paid for an order or not.