next-pwa set pwa homepage to subdirectory

Question

I need my PWA to open at /app instead of /. It opens at / and offers the install prompt even with my configuration below.

Am I missing some configuration aside from start_url ?

next.config.js

const withPWA = require("next-pwa");
const runtimeCaching = require("next-pwa/cache");
/** @type {import('next').NextConfig} */
module.exports = withPWA({
  pwa: {
    dest: "public",
    runtimeCaching,
    scope: "/app/",
  },
});

/public/manifest.json --shortened colors and icons

{
  "theme_color": "#",
  "background_color": "#",
  "display": "standalone",
  "start_url": "/app/",
  "scope": "/app/",
  "name": "",
  "short_name": "",
  "icons": [...]
}