to make it work you need a .env file like so with your Ethereum account's private key, your Infura web3 provider"s project id, and your ethercan api key to get your contract verified :
export PRIVATE_KEY=0x12345678901234567890
export WEB3_INFURA_PROJECT_ID=blablablablablablabla
export ETHERSCAN_TOKEN=blablablablablablabla