Examine source code of Web Vitals Tracker

{
  "manifest_version": 2,
  "name": "Web Vitals Tracker",
  "version": "1.3",
  "description": "Measure Core Web Vitals (LCP, FID, CLS, etc.) directly in the browser.",
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Web Vitals"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7c66ce4d-aa9e-4261-a726-19f4dfab1efa}"
    }
  }
}