get usage

curl --request GET \
  --url https://api.unprice.dev/v1/customer/{customerId}/getUsage \
  --header 'Authorization: Bearer <token>'

{
  "planVersion": {
    "description": "<string>",
    "flatPrice": "<string>",
    "currentTotalPrice": "<string>",
    "billingConfig": {
      "name": "<string>",
      "billingInterval": "month",
      "billingIntervalCount": 6,
      "billingAnchor": 16,
      "planType": "recurring"
    }
  },
  "subscription": {
    "planSlug": "<string>",
    "status": "idle",
    "currentCycleEndAt": 123,
    "timezone": "<string>",
    "currentCycleStartAt": 123,
    "prorationFactor": 123,
    "prorated": true
  },
  "phase": {
    "trialEndsAt": 123,
    "endAt": 123,
    "trialDays": 123,
    "isTrial": true
  },
  "entitlement": [
    {
      "featureSlug": "<string>",
      "featureType": "flat",
      "isCustom": true,
      "limit": 123,
      "usage": 123,
      "freeUnits": 123,
      "max": 123,
      "units": 123,
      "included": 123,
      "featureVersion": {
        "id": "<string>",
        "projectId": "<string>",
        "createdAtM": 123,
        "updatedAtM": 123,
        "planVersionId": "<string>",
        "featureId": "<string>",
        "featureType": "flat",
        "config": {
          "tiers": [
            {
              "unitPrice": {
                "dinero": {
                  "amount": 123,
                  "currency": {
                    "code": "<string>",
                    "base": 123,
                    "exponent": 123
                  },
                  "scale": 123
                },
                "displayAmount": "<string>"
              },
              "flatPrice": {
                "dinero": {
                  "amount": 123,
                  "currency": {
                    "code": "<string>",
                    "base": 123,
                    "exponent": 123
                  },
                  "scale": 123
                },
                "displayAmount": "<string>"
              },
              "firstUnit": 2,
              "lastUnit": 2
            }
          ],
          "price": {
            "dinero": {
              "amount": 123,
              "currency": {
                "code": "<string>",
                "base": 123,
                "exponent": 123
              },
              "scale": 123
            },
            "displayAmount": "<string>"
          },
          "usageMode": "tier",
          "tierMode": "volume",
          "units": 2
        },
        "metadata": {
          "stripeProductId": "<string>",
          "realtime": true
        },
        "aggregationMethod": "sum",
        "order": 123,
        "defaultQuantity": 1,
        "limit": 123,
        "hidden": true,
        "feature": {
          "id": "<string>",
          "projectId": "<string>",
          "createdAtM": 123,
          "updatedAtM": 123,
          "slug": "<string>",
          "code": 123,
          "title": "<string>",
          "description": "<string>"
        }
      },
      "price": "<string>"
    }
  ]
}