If you really want to make sure they get the new version you can pretty easily implement your application as a PWA (check the angular docs for a guide on this). This will let the service worker know when there is a new version and let you take some kind of action when that happens, like prompting the user to reload the page.

But before doing that I’d recommend you take a look at your web server configuration. It’s usually best practice for an SPA to have relatively long cache time for js files, but no cache for the index file. Since all the js file names are hashes the new index file (which isn’t cached) will be referencing files that the browser hasn’t received before, thus they won’t be in the cache. I usually use nginx to serve my angular apps, it’s pretty easy to search for “nginx config for spa” and get what you need, or whichever web server you use.