DUO replace username

rule.js

function (user, context, callback) {

  var CLIENTS_WITH_MFA = ['REPLACE_WITH_YOUR_CLIENT_ID'];
  // run only for the specified clients
  if (CLIENTS_WITH_MFA.indexOf(context.clientID) !== -1) {
 
    // uncomment the following if clause in case you want to request a second factor only from user's that have user_metadata.use_mfa === true
    // if (user.user_metadata && user.user_metadata.use_mfa){
      context.multifactor = {
        //required
        provider: 'duo',
        ikey: 'DIXBMN...LZO8IOS8',
        skey: 'nZLxq8GK7....saKCOLPnh',
        host: 'api-3....049.duosecurity.com',

        // optional, defaults to true. Set to false to force DuoSecurity every time. 
        // See https://auth0.com/docs/multifactor-authentication/custom#change-the-frequency-of-authentication-requests for details
        allowRememberBrowser: false,

        // optional. Use some attribute of the profile as the username in DuoSecurity. This is also useful if you already have your users enrolled in Duo.
        username: user.user_id.replace(/\|/ig, ''),

        // optional. Admin credentials. If you provide an Admin SDK type of credentials. auth0 will update the realname and email in DuoSecurity.
        // admin: {
        //  ikey: 'DIAN...NV6UM',
        //  skey: 'YL8OVzvoeeh...I1uiYrKoHvuzHnSRj'
        // },
      };
    // }
  }

  callback(null, user, context);
}