twoFactorAuthClient.js

import { Accounts } from 'meteor/accounts-base';

class LoginForm extends React.Component {
  state = {
    email: '',
    password: '',
    token: '',
    requiresTwoFactor: false,
    loading: false,
  };

  onSubmit = () => {
    this.setState({ loading: true });
    const { email, password, token } = this.state;
    
    Accounts.callLoginMethod({
      methodArguments: [{
        user: { email },
        twoFactorPassword: Accounts._hashPassword(password),
        twoFactorToken: token ? Number(token) : null,
      }],
      userCallback: e => e && (
        e.error === 'two-factor-required' ?
          this.setState({ requiresTwoFactor: true, loading: false }) :
          throw e,
    });
  };

  render = () => (…)
}