curl --request POST \
  --url https://api.voxo.co/v2/admin/number-porting/order-add-document \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form orderId=123 \
  --form 'documents=<unknown>'

{
  "results": [
    {
      "filename": "<string>",
      "documentId": "<string>",
      "status": "<string>",
      "message": "<string>"
    }
  ]
}