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

{
  "subscriptionItemFeature": {
    "id": "<string>",
    "createdAt": "<string>",
    "updatedAt": "<string>",
    "createdByCommit": "<string>",
    "updatedByCommit": "<string>",
    "livemode": true,
    "subscriptionItemId": "<string>",
    "featureId": "<string>",
    "productFeatureId": "<string>",
    "type": "<string>",
    "amount": null,
    "usageMeterId": null,
    "renewalFrequency": null,
    "expiredAt": "<string>",
    "detachedAt": "<string>",
    "detachedReason": "<string>",
    "name": "<string>",
    "slug": "<string>"
  }
}