curl --request GET \
  --url https://app.flowglad.com/api/v1/purchases/{id} \
  --header 'Authorization: <api-key>'

{
  "purchase": {
    "id": "<string>",
    "createdAt": "<string>",
    "updatedAt": "<string>",
    "createdByCommit": "<string>",
    "updatedByCommit": "<string>",
    "livemode": true,
    "name": "<string>",
    "status": "open",
    "customerId": "<string>",
    "organizationId": "<string>",
    "billingCycleAnchor": "<string>",
    "priceId": "<string>",
    "quantity": "<any>",
    "priceType": "<string>",
    "trialPeriodDays": "<any>",
    "pricePerBillingCycle": "<any>",
    "intervalUnit": "day",
    "intervalCount": "<any>",
    "firstInvoiceValue": "<any>",
    "totalPurchaseValue": "<any>",
    "bankPaymentOnly": true,
    "purchaseDate": "<string>",
    "endDate": "<string>",
    "proposal": "<string>",
    "archived": true,
    "billingAddress": "<string>",
    "metadata": {}
  }
}