The add-on can auto sync your balances from Bitcoin & Ethereum wallets with ERC20 , Coinbase, Binance, Kraken, HitBTC, KuCoin, Bittrex, Poloniex and Bitfinex exchanges.
All you need to do is setup your API keys for particular exchange under settings and you are done. All API keys are stored in the Google's PropertiesService
of the spreadsheet for which the add-on is activated.
Only owner of the spreadsheet have access to the API keys.