curl --request POST \
  --url https://api.meetcampfire.com/rr/api/v1/contracts/{contract_id}/subscriptions \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "contract": 123,
  "is_contract_amendment": true,
  "start_date": "2023-12-25",
  "end_date": "2023-12-25",
  "mrr": 0,
  "quantity": 0,
  "rate": 0,
  "notes": "<string>",
  "use_daily_accounting": true,
  "use_catchup": true,
  "catchup_date": "2023-12-25",
  "invoice_calculation": "FIXED_RATE",
  "product": 123,
  "modified_subscription": 123
}
'

{
  "id": 123,
  "is_deleted": false,
  "deleted_at": "2023-11-07T05:31:56Z",
  "lines": "<string>",
  "product_name": "<string>",
  "product_bundle": "<string>",
  "product_bundle_name": "<string>",
  "contract_product_bundle": {
    "id": 123,
    "source_bundle_name": "<string>",
    "total_amount": 0,
    "lines": [
      {
        "id": 123,
        "product": 123,
        "product_name": "<string>",
        "amount": 0,
        "percentage": "<string>",
        "original_percentage": 0
      }
    ],
    "source_bundle": 123,
    "currency": "<string>"
  },
  "total_value": 0,
  "last_modified_at": "2023-11-07T05:31:56Z",
  "created_at": "2023-11-07T05:31:56Z",
  "customer": 123,
  "contract": 123,
  "is_contract_amendment": true,
  "start_date": "2023-12-25",
  "end_date": "2023-12-25",
  "mrr": 0,
  "quantity": 0,
  "rate": 0,
  "notes": "<string>",
  "use_daily_accounting": true,
  "use_catchup": true,
  "catchup_date": "2023-12-25",
  "invoice_calculation": "FIXED_RATE",
  "product": 123,
  "modified_subscription": 123
}