curl --request POST \
  --url https://sandbox-api.shipbob.com/2026-01/shipment:batchCancel \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'shipbob_channel_id: <shipbob_channel_id>' \
  --data '
{
  "shipment_ids": [
    0
  ]
}
'

{
  "results": [
    {
      "action": "Cancel",
      "is_success": true,
      "reason": "string",
      "shipment_id": 0
    }
  ]
}