Examine source code of Page Info Viewer

{
  "manifest_version": 2,
  "name": "Page Info Viewer",
  "version": "1.3",
  "description": "View page info, meta tags, SEO data, schema, links, phone numbers, and emails.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon48.png",
      "96": "icon96.png"
    }
  },
  "icons": {
    "48": "icon48.png",
    "96": "icon96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "pageinfoviewer@addon.test",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}