curl --request PATCH \
  --url https://api.example.com/api/v1/cancellation-policies/{policy_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <x-api-key>' \
  --data '
{
  "name": "<string>",
  "refund_type": "<string>",
  "refund_percentage": 123,
  "refund_window_days": 123,
  "prorate_refund": true,
  "cancellation_fee": 123,
  "apply_to_existing": true,
  "is_default": true,
  "extra_data": {}
}
'

{
  "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "name": "<string>",
  "refund_type": "<string>",
  "refund_percentage": 123,
  "refund_window_days": 123,
  "prorate_refund": true,
  "cancellation_fee": 123,
  "apply_to_existing": true,
  "is_default": true,
  "created_at": "3c90c3cc-0d44-4b50-8888-8dd25736052a"
}