@sateeshk9319722,
You can integrate build scripts in the package.json where a specific build script will build the environment variables into the bundle.js during webpack or gulp JavaScript compilation.
Take example: https://github.com/adobe/aem-project-archetype/blob/master/src/main/archetype/ui.frontend.angular/pa...
Or if your environment values are stored in the AEM server as JSON, you can utilise run modes, and OSGI configurations, to render the path of the configuration apart of the HTML page, then use JavaScript to make an XHR (request) to the request from the path.
<div class="global-config" data-global-config="/en-gb.global.json"></div>