Type the following say in your head tag or bottom page of your index page to register the service worker.

register.service.worker

Type the following in your empty service-worker.js file to import Workbox and add cache strategies to it, press enter to get the snippet.

workbox.cdn

workbox.strategies

Add workbox window to your index page to help with faster service worker registration by typing the following at the bottom of your index page as well.

workbox.window

Best for static sites and most probably web apps that do not have a huge production scale need, type the following keyword in the empty service-worker.js and press enter to get the snippet.

basic service worker

Now type the following in your empty app.webmanifest file and press enter to get the snippet. Remember to have your icons already as shown in the app.webmanifest

add.web.manifest

Now remember to add web manifest to everyone of those pages in your web app by typing the following in the head tags.

add web manifest to pages

Add theme color to the same pages in the head tag to using the keyword below

theme color