How can I pass the extra data of type string while redirecting the user to my simple checkout form so that when the webhook notification or relay response is trigger we get that data in the request body
I want to identify the user that this is the same user who did the purchase with his unique Id in my platform
refId is a first level property of transactionRequest. The documentation says that if you pass it in the transactionRequest, it will be returned in the transactionResponse as refId, at the same level in the object.
String, up to 20 characters.