Callback notification interface (customized by merchant)
POST
notifyUrl
Signature rules: After JSONizing the request parameters (parameters are in order), put the obtained signature in the header, obtain the signature directly from the response header, and use verifyEcdsaSignature() in the tool class to verify the signature.
This interface is implemented by the merchant itself. After receiving our callback, it has nothing to do with the business status. Once you receive our notification, please return the string OK. There is no need to return JSON format data, and it is handled by the merchant. Ensure the idempotence of the business, multiple notifications will only be processed once