rinkeby v3 used
DATABASE_URL=postgres://localhost/plasma
CHAIN_ID=4
-WEB3_URL= # https://rinkeby.infura.io/{infura project id} or http://localhost:8545
+WEB3_URL= # https://rinkeby.infura.io/v3/{infura project id} or http://localhost:8545
SENDER_ACCOUNT= # sender address for server without leading 0x, e.g. Ef3300000779Dd6a21234B42D3B04F638251746c
PRIVATE_KEY= # private key without leading 0x
