Examine source code of Document View Backdrop

{
  "manifest_version": 3,
  "name": "Document View Backdrop",
  "version": "1.0",
  "description": "A document view backdrop displayed inside the extension popup.",
  "action": {
    "default_popup": "popup.html",
    "default_title": "Document View Backdrop",
    "default_icon": {
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "icons": {
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "documentviewbackdrop@example.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}