.env file. It's a private key of the account that will deploy the contracts and should be gitignored.KEY_TESTNET or bsc KEY_MAINNETETHERSCAN_API_KEY in .env file. It's an API key for etherscan.yarn in root directoryNETWORK=$NETWORK yarn zx v3-deploy.mjs where $NETWORK is either eth, goerli, bscMainnet, bscTestnet or hardhat (for local testing)NETWORK=$NETWORK yarn zx v3-verify.mjs where $NETWORK is either eth, goerli, bscMainnet, bscTestnet or hardhat (for local testing)