const BLOCKSDK = require("blocksdk-js");
const client = new BLOCKSDK(
  "Node_RPC_TOKEN",
  "https://mainnet-api.blocksdk.com"
);

client.undefined.GetBlockChainInfo().then(
  answer => console.log(answer)
);

client.undefined.GetBlock("block" : "blockNumber or blockHash").then(
  answer => console.log(answer)
);