Examine source code of PDF Saver

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_icon": {
      "64": "icons/icon48.png"
    },
    "default_title": "PDF Saver"
  },
  "description": "The best Web Page PDF Saver Add-on for Firefox, save web pages as PDF in one click.",
  "icons": {
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "sidebar_action": {
    "default_icon": "icons/icon48.png",
    "default_title": "PDF Saver",
    "default_panel": "popup.html"
  },
  "manifest_version": 3,
  "name": "PDF Saver",
  "permissions": [
    "storage",
    "contextMenus",
    "tabs",
    "declarativeNetRequest",
    "downloads",
    "downloads.open"
  ],
  "content_scripts": [
    {
      "css": [
        "css/content.css"
      ],
      "matches": [
        "https://pdfcrowd.com/*"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "js": [
        "jquery-3.4.1.min.js",
        "content.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "all_frames": true,
      "run_at": "document_end"
    }
  ],
  "version": "10.9",
  "browser_specific_settings": {
    "gecko": {
      "id": "{8bdc204a-553d-4d69-502d-706330d78dcf}"
    }
  },
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ]
}