This endpoint will reject a pending award transaction and change the status of the transaction from pending to rejected. This action will not change the available points balance of the member.
The transaction ID is the internal ID that Zinrelo assigns to each transaction. It is expected that the system calling the API knows what the id of the transaction is which means it would have been stored in the system earlier.
Note: You can get a Transaction ID through List all Transactions API. It is the unique ID that every transaction is associated with.