Examine source code of Get Similarweb Info

{
  "author": "igorlogius",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "icons": {
    "128": "icon.png"
  },
  "manifest_version": 2,
  "name": "Get Similarweb Info",
  "permissions": [
    "activeTab",
    "https://www.similarweb.com/website/*",
    "webRequest",
    "webRequestBlocking",
    "webNavigation"
  ],
  "sidebar_action": {
    "default_panel": "sidebar.html",
    "open_at_install": false,
    "default_icon": "icon.png"
  },
  "version": "1.1.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "{874458b6-29fc-4256-94f5-24a8850304dc}"
    }
  }
}