Examine source code of BreakTimeExtended

{
  "manifest_version": 3,
  "name": "BreakTimeExtended",
  "description": "Run Brick Breaker (aka Breakout) inside your Google and Outlook Calendars!",
  "version": "2",
  "action": {
    "default_icon": {
      "16": "images/icon-16.png",
      "32": "images/icon-32.png",
      "48": "images/icon-48.png",
      "128": "images/icon-128.png"
    }
  },
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "background": {
    "scripts": [
      "code/background.js"
    ],
    "service_worker": "code/background.js",
    "matches": [
      "https://outlook.*.com/calendar/*",
      "https://calendar.google.com/*"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "hh-13@github.com"
    }
  }
}