x-api-key: ********************
{ "transactionId": "string", "userId": "string" }
curl --location --request POST 'https://api.b2b.retter.io/5p1hp1d2t/CALL/Promotion/cancelTransaction/' \ --header 'Content-Type: application/json' \ --header 'x-api-key;' \ --data-raw '{ "transactionId": "string", "userId": "string" }'
{ "message": "string" }