Examine source code of Tab Limit - 10 tabs

{
  "manifest_version": 3,
  "name": "Tab Limit",
  "version": "1.0",
  "description": "Limits the number of browser tabs you can open at the same time to 10.",
  "browser_specific_settings": {
    "gecko": {
      "id": "temporary-id@tab-limit",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "tab-limit.js"
    ]
  },
  "permissions": [
    "tabs",
    "notifications"
  ]
}