Examine source code of New Tab Redirect

{
  "manifest_version": 3,
  "name": "New Tab Redirect",
  "version": "2.6.0",
  "description": "Any website in a new tab page. This add-on automatically opens your website every time you open a new tab in your browser.",
  "icons": {
    "512": "icon512x512.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ca76a51e-39c5-426e-a65a-17331611382e}",
      "strict_min_version": "109.0"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "action": {
    "default_popup": "options.html",
    "default_icon": {
      "512": "icon512x512.png"
    }
  },
  "chrome_url_overrides": {
    "newtab": "new-tab-redirect.html"
  }
}