curl --request GET \
  --url https://api.messari.io/metrics/v2/networks/metrics \
  --header 'X-Messari-API-Key: <api-key>'

{
  "data": {
    "datasets": [
      {
        "granularities": [
          ""
        ],
        "metrics": [
          {
            "description": "<string>",
            "is_timestamp": true,
            "name": "<string>",
            "slug": "<string>"
          }
        ],
        "slug": "<string>"
      }
    ]
  },
  "error": "<string>"
}