Examine source code of Extra sounds

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "2.2",
  "homepage_url": "https://jnsoft.ru/en/articles/other/extrasounds/",
  "icons": {
    "48": "icons/link-48.png"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "applications": {
    "gecko": {
      "id": "extrasounds@tiflohelp.ru",
      "strict_min_version": "57.0"
    }
  },
  "permissions": [
    "notifications",
    "webNavigation",
    "downloads",
    "storage"
  ],
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "default_locale": "en"
}