Examine source code of New Tab Workout

{
  "manifest_version": 3,
  "name": "New Tab Workout",
  "version": "0.2",
  "description": "Adds daily workouts to your new tab page.",
  "author": "dnl-dft",
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "dnldft@proton.me"
    }
  }
}