curl --request POST \
  --url https://sbx.api.easybilling.cloud/payment-hub/api/refund \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "transactionId": "275374c30d584b599c57aef0ccd03ada",
  "requestId": "r1e2q3u4e5s6t7i8d9",
  "amount": "100"
}
'

{
  "transactionId": "<string>",
  "status": "<string>"
}