blockscout/apps/explorer/config/dev/arbitrum.exs

import Config

config :explorer,
  json_rpc_named_arguments: [
    transport: EthereumJSONRPC.HTTP,
    transport_options: [
      http: EthereumJSONRPC.HTTP.HTTPoison,
      url: System.get_env("ETHEREUM_JSONRPC_HTTP_URL") || "http://localhost:8545",
      http_options: [recv_timeout: :timer.minutes(1), timeout: :timer.minutes(1), hackney: [pool: :ethereum_jsonrpc]]
    ],
    variant: EthereumJSONRPC.Arbitrum
  ],
  subscribe_named_arguments: [
    transport: EthereumJSONRPC.WebSocket,
    transport_options: [
      web_socket: EthereumJSONRPC.WebSocket.WebSocketClient,
      url: System.get_env("ETHEREUM_JSONRPC_WS_URL")
    ],
    variant: EthereumJSONRPC.Arbitrum
  ]