curl --request GET \
  --url https://api.example.com/payment/usage/{api_token} \
  --header 'Authorization: Bearer <token>'

{
  "months": [
    {
      "period": "<string>",
      "interval": {
        "fr": 0,
        "to": 4000000000000
      },
      "items": [
        {
          "model": {
            "provider": "<string>",
            "model_name": "<string>",
            "task": "<string>",
            "plan_id": "<string>",
            "private": false
          },
          "units": 123,
          "rate": 123,
          "cost": 123,
          "pricing_type": "<string>",
          "interval": {
            "fr": 0,
            "to": 4000000000000
          },
          "discount": {
            "name": "<string>",
            "description": "<string>"
          }
        }
      ],
      "total_cost": 123,
      "invoice_id": "NOT_FINAL"
    }
  ],
  "initial_month": "<string>"
}