curl --request POST \
  --url https://app.coverwhale.com/api/v1/submission/{displayId}/{transactionId}/cancel \
  --header 'AccessToken: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "cancellation_reason": "<string>",
  "cancel_reason_others": "<string>"
}
'

{
  "status": "success",
  "submission_number": "<string>",
  "transaction_id": 123,
  "submission_status": "<string>"
}