Examine source code of PDF Grabber

{
  "manifest_version": 3,
  "name": "Zen PDF Grabber",
  "version": "1.2.0",
  "description": "Find and download all PDFs on the current page.",
  "permissions": [
    "activeTab",
    "scripting",
    "downloads",
    "storage"
  ],
  "optional_host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "pdf-grabber@zen-user.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}