curl --request POST \
  --url https://api.absentify.com/api/v1/requests/{id}/cancel \
  --header 'Content-Type: application/json' \
  --header 'X-API-KEY: <api-key>' \
  --data '{
  "cancel_reason": "<string>"
}'

{
  "success": true,
  "message": "<string>"
}