Examine source code of Todo List Extension

{
  "manifest_version": 3,
  "name": "Todo List Extension",
  "version": "1.0",
  "description": "A todo list extension to get your daily todos list saved in txt file",
  "permissions": [
    "storage"
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'none';"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "f59b3d956759cb3652cf96e938b959c62140d392@levi.com",
      "strict_min_version": "58.0"
    }
  }
}