curl --request POST \
  --url https://api.fungies.io/v0/subscriptions/create \
  --header 'Content-Type: application/json' \
  --header 'x-fngs-public-key: <api-key>' \
  --header 'x-fngs-secret-key: <api-key>' \
  --data '
{
  "items": [
    {
      "name": "<string>",
      "unitPrice": 123,
      "quantity": 1,
      "offerId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "price": 8.988465674311579e+307,
      "value": 8.988465674311579e+307
    }
  ],
  "userId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "userEmail": "jsmith@example.com",
  "backdateStartDate": 4503599627370495,
  "billingCycleAnchor": 4503599627370495,
  "trialEnd": 4503599627370495,
  "skipTrial": false,
  "skipNotifications": false
}
'

{
  "status": "<string>",
  "data": {
    "subscription": {
      "id": "<string>",
      "createdAt": 4503599627370495,
      "currentIntervalEnd": 4503599627370495,
      "currentIntervalStart": 4503599627370495,
      "orderId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "orderNumber": "<string>",
      "order": {
        "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "number": "<string>",
        "object": "order"
      },
      "object": "subscription",
      "cancelAtIntervalEnd": false,
      "canceledAt": null,
      "userId": null,
      "user": null,
      "lastPaymentId": null,
      "lastPaymentNumber": null,
      "lastPayment": null
    }
  }
}