curl --request POST \
  --url https://app.flowglad.com/api/v1/usage-events/bulk \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '{
  "usageEvents": [
    {
      "subscriptionId": "<string>",
      "amount": 123,
      "usageDate": 0,
      "transactionId": "<string>",
      "properties": {},
      "priceId": "<string>",
      "priceSlug": "<string>"
    }
  ]
}'

{
  "usageEvents": [
    {
      "id": "<string>",
      "createdAt": 0,
      "updatedAt": 0,
      "livemode": true,
      "customerId": "<string>",
      "subscriptionId": "<string>",
      "usageMeterId": "<string>",
      "billingPeriodId": "<string>",
      "amount": 123,
      "usageDate": 0,
      "transactionId": "<string>",
      "priceId": "<string>",
      "properties": {}
    }
  ]
}