truffle-config.js

const HDWalletProvider = require('@truffle/hdwallet-provider');
const fs = require('fs');
const mnemonic = "beyond ahead broom explain path blossom real turtle exact moment treat coyote";


module.exports = {
  networks: {
    development: {
      host: "127.0.0.1",     // Localhost (default: none)
      port: 8545,            // Standard Ethereum port (default: none)
      network_id: "*",       // Any network (default: none)
    },
    matic: {
      provider: () => new HDWalletProvider(mnemonic, `https://rpc-mumbai.maticvigil.com`),
      network_id: 80001,
      confirmations: 2,
      timeoutBlocks: 200,
      skipDryRun: true
    },
  },

  // Set default mocha options here, use special reporters etc.
  mocha: {
    // timeout: 100000
  },

  // Configure your compilers
  compilers: {
    solc: {
        version: "^0.4.26",
    }
  },
  contracts_directory: './contracts/',
  contracts_build_directory: './build/contracts/',
  compilers: {
    solc: {
      optimizer: {
        enabled: true,
        runs: 200
      },
      evmVersion: "petersburg"
    }
  }
}