curl --request PUT \
  --url https://api.getcargo.io/v1/billing/subscription/topup \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "enabled": true,
  "threshold": 123,
  "creditsCount": 123
}
'

{
  "subscription": {
    "uuid": "<string>",
    "workspaceUuid": "<string>",
    "provider": "stripe",
    "customerOrbId": "<string>",
    "customerStripeId": "<string>",
    "subscriptionStatus": "<string>",
    "subscriptionStripeId": "<string>",
    "subscriptionAvailableCreditsCount": 123,
    "subscriptionCreditsUsedCount": 123,
    "additionalAvailableCreditsCount": 123,
    "hasCredits": true,
    "creditsOverageBehaviors": [
      {
        "unit": "billing.credits",
        "action": "deny"
      }
    ],
    "createdAt": "<string>",
    "updatedAt": "<string>",
    "plan": "self-serve",
    "cadence": "monthly",
    "fixedPrice": 123,
    "conversionRate": 123,
    "startAt": "<string>",
    "resetAt": "<string>",
    "endAt": "<string>",
    "hasPendingChange": true,
    "futureChange": {
      "cadence": "monthly",
      "fixedPrice": 123,
      "creditsCount": 123,
      "conversionRate": 123,
      "startAt": "<string>",
      "endAt": "<string>"
    },
    "topup": {
      "creditsCount": 123,
      "threshold": 123
    }
  }
}