curl --request POST \
  --url https://api.sonderplan.com/v2/booking/bulk \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "save": {
    "common_properties": [
      {
        "calendar_subscription_id": 234982,
        "resources": [
          {
            "id": 34982
          }
        ],
        "project": [
          {
            "id": 239909
          }
        ],
        "status": [
          {
            "id": 40123
          }
        ],
        "client": [
          {
            "uuid": "p209809"
          }
        ]
      }
    ],
    "columns": [
      "external_id",
      "start",
      "end",
      "name",
      "notes"
    ],
    "values": [
      "<unknown>"
    ]
  },
  "delete": {
    "id": [
      98923,
      19812,
      23838
    ],
    "external_id": [
      "1234j@kf9i094-090-9435aasdas"
    ],
    "calendar_subscription_id": [
      989232349
    ]
  }
}
'

{
  "save": {
    "success": [
      {
        "id": 2340,
        "external_id": "1234j@kf9i094-090-9435aasdas"
      }
    ]
  },
  "delete": {
    "id": {
      "success": true
    },
    "external_id": {
      "success": true
    },
    "calendar_subscription_id": {
      "success": true
    }
  }
}