authentication.js

<script type="text/javascript">
  window.zESettings = {
    webWidget: {
      authenticate: {
        jwtFn: function(callback) {
          // Fetch your jwt token and then call our supplied callback below.
          callback('YOUR_JWT_TOKEN');
        },
        chat: {
          jwtFn: function(callback) {
            // Fetch your jwt token and then call our supplied callback below.
            callback('YOUR_JWT_TOKEN');
          }
        }
      }
    }
  };
</script>