Examine source code of LeetNotion Sync

{
  "manifest_version": 3,
  "name": "LeetNotion Sync",
  "version": "2.0",
  "description": "Save completed LeetCode problems to Notion.",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "https://leetcode.com/*",
    "https://api.notion.com/*"
  ],
  "action": {
    "default_icon": {
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    },
    "default_title": "LeetNotion Sync",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://leetcode.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "leetnotion-sync@yourdomain.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}