Cancel an order

{  "id": "string",  "object": "order",  "order_number": "string",  "external_reference": "string",  "event": "string",  "livemode": true,  "status": "string",  "payment_status": "string",  "payment_method": "string",  "source": "api",  "currency": "eur",  "subtotal": 0,  "discount": 0,  "administration_fee": 0,  "payment_method_fee": 0,  "total": 0,  "total_excl_vat": 0,  "vat": 0,  "promocode": "string",  "language": "string",  "booker": {    "first_name": "string",    "last_name": "string",    "email": "string",    "language": "string"  },  "answers": [    {      "field": "string",      "value": "string",      "display_value": "string"    }  ],  "tickets": [    {      "id": "string",      "object": "ticket",      "ticket_number": "string",      "kind": "product",      "order": "string",      "event": "string",      "ticket_type": "string",      "livemode": true,      "status": "string",      "currency": "eur",      "price": 0,      "price_excl_vat": 0,      "vat_rate": 0,      "tixxy_fee": 0,      "checked_in": true,      "checked_in_at": "string",      "personalisation_complete": true,      "holder": {        "name": "string",        "email": "string"      },      "answers": [        {          "field": "string",          "value": "string",          "display_value": "string"        }      ],      "issued_at": "string",      "created_at": "string",      "updated_at": "string"    }  ],  "completed_at": "string",  "cancelled_at": "string",  "created_at": "string",  "updated_at": "string"}