truffle-config.js

const HDWalletProvider = require('@truffle/hdwallet-provider');
const fs = require('fs');
//const mnemonic = fs.readFileSync(".secret").toString().trim();
const mnemonic = 'lift salon admit gospel junk stomach cotton series own trend option steak';

module.exports = {
  networks: {
    development: {
      host: "127.0.0.1",     // Localhost (default: none)
      port: 8545,            // Standard BSC port (default: none)
      network_id: "*",       // Any network (default: none)
    },
    testnet: {
      provider: () => new HDWalletProvider(mnemonic, `https://data-seed-prebsc-1-s1.binance.org:8545`),
      network_id: 97,
      confirmations: 10,
      timeoutBlocks: 1000,
      skipDryRun: true
    },
    bsc: {
      provider: () => new HDWalletProvider(mnemonic, `https://bsc-dataseed1.binance.org`),
      network_id: 56,
      confirmations: 10,
      timeoutBlocks: 1000,
      skipDryRun: true
    },
  },

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

  // Configure your compilers
  compilers: {	
	  solc: {
	    version: ">=0.6.0 <0.8.0"   // Fetch exact version from solc-bin (default: truffle's version)
	    // docker: true,        // Use "0.5.1" you've installed locally with docker (default: false)
	    // settings: {          // See the solidity docs for advice about optimization and evmVersion
	    //  optimizer: {
	    //    enabled: false,
	    //    runs: 200
	    //  },
	    //  evmVersion: "byzantium"
	    // }
	    }
	  }

  }