Examine source code of Download Star

{
  "manifest_version": 2,
  "name": "Download Star",
  "version": "2.0.5",
  "applications": {
    "gecko": {
      "id": "{8cc0b007-e40b-46e8-9e50-e3bf021c94ab}",
      "strict_min_version": "63.0"
    }
  },
  "default_locale": "en",
  "description": "__MSG_manifestDescription__",
  "icons": {
    "48": "icons/icon-black.svg",
    "96": "icons/icon-black.svg"
  },
  "permissions": [
    "activeTab",
    "downloads",
    "storage"
  ],
  "optional_permissions": [
    "<all_urls>"
  ],
  "browser_action": {
    "browser_style": false,
    "default_icon": "icons/icon-light.svg",
    "default_title": "Download Star",
    "theme_icons": [
      {
        "light": "icons/icon-light.svg",
        "dark": "icons/icon-dark.svg",
        "size": 32
      }
    ]
  },
  "background": {
    "scripts": [
      "background/download.js"
    ]
  },
  "options_ui": {
    "browser_style": false,
    "page": "options/options.html",
    "open_in_tab": true
  }
}