curl --request GET \
  --url https://api.blockworks.com/v1/assets/{idOrSlug}/supply \
  --header 'x-api-key: <api-key>'

{
  "circulating": 120702472.20949,
  "liquid": 0,
  "total": 120702572.39159,
  "asset_code": "ETH",
  "asset_slug": "ethereum"
}