Ember-index is not producing index.jsp

i am trying to use ember-index add on to generate index.jsp file instead of index.html. i have installed the ember-index addon and did the required changes as well.

My config/environment.js file looks like below /* eslint-env node */

'use strict';

module.exports = function(environment) {
  let ENV = {
    modulePrefix: 'user-profile',
    output: 'index.jsp',
    environment,
    rootURL: '/',
    locationType: 'hash',
    EmberENV: {
      FEATURES: {
        // Here you can enable experimental features on an ember canary build
        // e.g. 'with-controller': true
      },
      EXTEND_PROTOTYPES: {
        // Prevent Ember Data from overriding Date.parse.
        Date: false
      }
    },
    'ember-index': {
        output: 'index.jsp',
        content: {
            file: 'example.txt',
            includeInOutput: true,
            includeInIndexHtml: false
        }
    },

    APP: {
      // Here you can pass flags/options to your application instance
      // when it is created
    }
  };
return ENV;
};

Also my example.txt file looks like

<meta content="Example">
<h2>html to jsp</h2>

and finally in my index.html i have added below snippet

But now when i am trying to build the ember project with ember build i am not able to see index.jsp file in my dist folder. Anyone has any idea why this is not working.