Examine source code of Delete Facebook Messages Fast

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "Delete Facebook Messages Fast",
  "short_name": "MsgEraser",
  "version": "1.0.0",
  "description": "Bulk delete or archive all Facebook Messenger chats, including Buy/Sell marketplace messages, with a single click.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": "icons/icon-128.png",
    "default_title": "Delete Facebook Messages Fast"
  },
  "background": {
    "service_worker": "background.js"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.facebook.com/*"
      ],
      "js": [
        "content/content.js"
      ],
      "css": [
        "content/content.css"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ]
}