truffle.js

const HDWalletProvider = require('@truffle/hdwallet-provider');
require('dotenv').config()

module.exports = {
  contracts_build_directory: "./src/build",
  networks: {
    development: {
      host: "127.0.0.1",
      port: 8545,
      network_id: "*"
    },
    rinkeby: {
      provider: () => new HDWalletProvider(process.env.REACT_APP_MNEMONIC, process.env.REACT_APP_INFURA_URL),
      network_id: 4,       // Ropsten's id
      gas: 5500000,        // Ropsten has a lower block limit than mainnet
      confirmations: 2,    // # of confs to wait between deployments. (default: 0)
      timeoutBlocks: 200,  // # of blocks before a deployment times out  (minimum/default: 50)
      skipDryRun: true     // Skip dry run before migrations? (default: false for public nets )
    },
  },
  compilers: {
    solc: {
      version: "0.8.10"
   }
 }
};