For the pre-create, cancel, refund, and query flows, you can integrate by implementing APIs. The following table shows the APIs that are used in Transaction QR Code Payment. Click View doc to see details of the request parameters, response, samples, and error codes.
Alipay does not recommend any order for implementing the APIs. However, to whitelist a payment integrator, Alipay requires the integrator to implement all APIs listed in this documentation.