curl --request GET \
  --url https://api.topograph.co/v2/billing/notifications/config \
  --header 'x-api-key: <api-key>'

{
  "lowBalanceEnabled": false,
  "lowBalanceEmailEnabled": true,
  "lowBalanceWebhookEnabled": true,
  "lowBalanceTiers": [
    {
      "tier": "warning",
      "cents": 100000
    }
  ],
  "globalHighUsageEnabled": false,
  "globalHighUsageEmailEnabled": true,
  "globalHighUsageWebhookEnabled": true,
  "globalHighUsagePeriodMinutes": 1440,
  "globalHighUsageTiers": [
    {
      "tier": "warning",
      "cents": 100000
    }
  ],
  "highUsageEnabled": false,
  "highUsageEmailEnabled": true,
  "highUsageWebhookEnabled": true,
  "highUsagePeriodMinutes": 1440,
  "highUsageTiers": [
    {
      "tier": "warning",
      "cents": 100000
    }
  ],
  "autoTopupNotificationsEnabled": false,
  "autoTopupEmailEnabled": true,
  "autoTopupWebhookEnabled": true
}