Callback notification interface (customized by the merchant)
POST
notifyUrl
Signature rules: After JSONifying the request parameters (parameters are ordered), the obtained signature is placed in the header. The signature can be directly obtained from the response header, and the verification method uses the verifyEcdsaSignature() method in the utility class.
The interface is implemented by the merchant themselves. After receiving our callback, regardless of the business status, as soon as you receive our notification, please return the string OK and no need to return JSON formatted data. The merchant is responsible for ensuring the idempotence of the business, and the notification is processed only once regardless of the number of times it is received.
