Converse opening a chat from API

HTML

<script src="https://cdn.conversejs.org/dist/converse.js"></script>
<link rel="stylesheet" href="https://cdn.conversejs.org/css/converse.min.css">

JavaScript

converse.plugins.add('myplugin', {
      initialize: function() {
        var _converse = this._converse;
        Promise.all([
            _converse.api.waitUntil('rosterContactsFetched'),
            _converse.api.waitUntil('chatBoxesFetched')
        ]).then(function() {
          // Note, [email protected] must be in your contacts roster!
          _converse.api.chats.open('[email protected]');
        });
      }
    });

    converse.initialize({
      bosh_service_url: 'https://ejabberd.astirling.co.uk/bosh/',
      show_controlbox_by_default: true,
      whitelisted_plugins: ['myplugin'],
      debug: true
    });