PWA Dynamic (Progressive Web App) put an "Install" option

I have implemented PWA. I have used PWA Dynamic(Progressive Web App) free plugins. I have uploaded sw.js & manifest.json files at SEO/metatags and followed the other steps mentioned in the doc but on load, it is not showing the install option. How can I achieve this?

[PWA Dynamic (Progressive Web App) Doc] : -
[manifest.json file]: -(
[sw.js file]: -(