Discussion on: How do you bypass browser cache on a new web app update?

What tech stack are you using for your app? There are a number of methods available but they depend on your stack. Here are some examples:

NPM
You can use npm to build your js file, concatenate, minify, etc. If you have a package.json, you may have a version property in it. When you run your build script, you can make reference to that version property. Here is an excerpt from my package.json file.

{
  "version": "1.0.0",
  "scripts": {
    // use rollup module to bundle all of my ES modules and create a new file
    // inside a /dist folder. I make reference to the version number using 
    // %npm_package_version%
    "bundle-es": "rollup public/js/main.js --format cjs --name 'js-bundle' --file public/dist/%npm_package_version%/js/main.js"
    "build": "npm run bundle-es"
}

Dynamic
If you are using a server-side language like PHP, .NET, Ruby, etc, you can output the script tag using the server-side language, but first read a version.txt file. Example:

#version.txt
1.0.0

Then use your server-side language to read that .txt file, to get the version. Then use server-side language to output the script tag for you.

<?php
$version = file_get_contents('/version.txt', true);
echo '<script src="script.js?v=' . $version . '"></script>';
?>