Examine source code of Pears Custom New Tab

{
  "manifest_version": 3,
  "name": "Pears Custom New Tab",
  "version": "1.0",
  "description": "Redirect your new tab to any http(s) URL, localhost, or LAN address",
  "icons": {
    "118": "icon.png"
  },
  "chrome_url_overrides": {
    "newtab": "redirect.html"
  },
  "permissions": [
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "Set Custom New Tab"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "custom-newtab-redirect-placeholder-id@example.com"
    }
  }
}