OptionalapiKey: stringYour Etherscan API key (works across all chains in V2)
Optionalchain: string | number | nullChain name (e.g. 'sepolia', 'arbitrum') or numeric chainid; defaults to Ethereum mainnet
Optionaltimeout: numberRequest timeout in milliseconds (default 10000)
Optionalrequest: TransportCustom HTTP transport; defaults to a built-in node:https/node:http request
Create an Etherscan API client.