Difference from requestOperation method - you can add memo or time bounds to your transaction

stellar-sign-example2.js

const StellarSign = require('stellar-sign');
const StellarSdk = require('stellar-sdk');

StellarSdk.Network.usePublicNetwork();
const server = new StellarSdk.Server('https://horizon.stellar.org');

server.loadAccount('GBR3RS2Z277FER476OFHFXQJRKYSQX4Z7XNWO65AN3QPRUANUASANG3L')
  .then(account => {

    const builder = new StellarSdk.TransactionBuilder(account, {
      memo: StellarSdk.Memo.text('test')
    });
    builder.addOperation(StellarSdk.Operation.createAccount({
      destination: 'GCL245KQK5CLXMPO2JJTG36HBC4XWLGEZ5GZPKKWPE6CBOD3D2IDLOTO',
      startingBalance: '2.01',
    }));

    StellarSign
      .setHorizonUrl('https://horizon.stellar.org')
      .useNetwork(StellarSdk.Networks.PUBLIC)
      .requestTransaction(
        StellarSdk.Keypair.fromSecret('...'),
        'umbre1*papayame.com',
        builder.build().toEnvelope().toXDR()
      )
      .then(tx => {
        // transaction xdr with payment request sent to umbre1, if he accepts - transaction will be signed and submitted to the network.
        console.log(tx);
      })
      .catch(err => {
        console.error(err);
      });

  });