curl --request GET \
  --url https://us.api.flexprice.io/v1/coupon-associations/{id} \
  --header 'x-api-key: <api-key>'

{
  "coupon": {
    "amount_off": "<string>",
    "created_at": "2023-11-07T05:31:56Z",
    "created_by": "<string>",
    "currency": "<string>",
    "duration_in_periods": 123,
    "environment_id": "<string>",
    "id": "<string>",
    "max_redemptions": 123,
    "metadata": {},
    "name": "<string>",
    "percentage_off": "<string>",
    "redeem_after": "<string>",
    "redeem_before": "<string>",
    "rules": {},
    "tenant_id": "<string>",
    "total_redemptions": 123,
    "updated_at": "2023-11-07T05:31:56Z",
    "updated_by": "<string>"
  },
  "coupon_id": "<string>",
  "created_at": "2023-11-07T05:31:56Z",
  "created_by": "<string>",
  "end_date": "2023-11-07T05:31:56Z",
  "environment_id": "<string>",
  "id": "<string>",
  "metadata": {},
  "start_date": "2023-11-07T05:31:56Z",
  "subscription_id": "<string>",
  "subscription_line_item_id": "<string>",
  "subscription_phase_id": "<string>",
  "tenant_id": "<string>",
  "updated_at": "2023-11-07T05:31:56Z",
  "updated_by": "<string>"
}