truffle.js

    ropsten: {
      provider: () =>
        new HDWalletProvider(
          process.env["MNEMONIC"],
          `https://ropsten.infura.io/v3/939fb730f6cd4449aeb9f101cca7277e`
        ),
      network_id: 3, // 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 )
    }