curl --request GET \
  --url https://api.getlago.com/api/v1/customers/{external_customer_id}/projected_usage \
  --header 'Authorization: Bearer <token>'

{
  "customer_projected_usage": {
    "from_datetime": "2022-07-01T00:00:00Z",
    "to_datetime": "2022-07-31T23:59:59Z",
    "issuing_date": "2022-08-01",
    "lago_invoice_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
    "currency": "EUR",
    "amount_cents": 123,
    "projected_amount_cents": 256,
    "taxes_amount_cents": 200,
    "total_amount_cents": 123,
    "charges_usage": [
      {
        "units": "1.0",
        "events_count": 10,
        "amount_cents": 123,
        "amount_currency": "EUR",
        "pricing_unit_details": {
          "amount_cents": 200,
          "short_name": "CR",
          "conversion_rate": "0.5"
        },
        "charge": {
          "lago_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
          "charge_model": "graduated",
          "invoice_display_name": "Setup"
        },
        "billable_metric": {
          "lago_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
          "name": "Storage",
          "code": "storage",
          "aggregation_type": "sum_agg"
        },
        "filters": [
          {
            "units": "0.9",
            "amount_cents": 1000,
            "events_count": 10,
            "invoice_display_name": "AWS eu-east-1",
            "pricing_unit_details": {
              "amount_cents": 200,
              "short_name": "CR",
              "conversion_rate": "0.5"
            },
            "values": {
              "region": [
                "us-east-1"
              ]
            }
          }
        ],
        "grouped_usage": [
          {
            "amount_cents": 1000,
            "events_count": 10,
            "units": "0.9",
            "pricing_unit_details": {
              "amount_cents": 200,
              "short_name": "CR",
              "conversion_rate": "0.5"
            },
            "grouped_by": {},
            "filters": [
              {
                "units": "0.9",
                "amount_cents": 1000,
                "events_count": 10,
                "invoice_display_name": "AWS eu-east-1",
                "pricing_unit_details": {
                  "amount_cents": 200,
                  "short_name": "CR",
                  "conversion_rate": "0.5"
                },
                "values": {
                  "region": [
                    "us-east-1"
                  ]
                }
              }
            ]
          }
        ]
      }
    ]
  }
}