Examine source code of Testaccount Manager

{
  "name": "Testaccount Manager",
  "version": "1.1.1",
  "description": "Simple testaccount manager or password manager for browsers.",
  "homepage_url": "https://github.com/JSHSJ/test-account-manager",
  "manifest_version": 2,
  "icons": {
    "16": "images/icon_16.png",
    "24": "images/icon_24.png",
    "32": "images/icon_32.png",
    "128": "images/icon_128.png"
  },
  "author": "Joshua Stübner & Lukas Koeller",
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "Testaccount Manager",
    "default_icon": {
      "16": "images/icon_16.png",
      "24": "images/icon_24.png",
      "32": "images/icon_32.png",
      "128": "images/icon_128.png"
    }
  },
  "options_ui": {
    "page": "index.html#options"
  },
  "permissions": [
    "activeTab",
    "storage",
    "unlimitedStorage"
  ],
  "optional_permissions": [
    "https://*/"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{80273266-4351-48eb-aa44-ff6ba17621e4}"
    }
  }
}