Examine source code of MeetKeep - Google Meet Timer

{
  "manifest_version": 2,
  "name": "MeetKeep - Google Meet Timer",
  "description": "Automatically injects a meeting timer into Google Meet.",
  "version": "1.3.4",
  "icons": {
    "16": "icon/16.png",
    "48": "icon/48.png",
    "128": "icon/128.png"
  },
  "homepage_url": "https://ibnumardini.github.io/meetkeep",
  "author": "Muhammad Fatkurozi",
  "permissions": [
    "storage",
    "https://meetkeep-analytics.mardini.workers.dev/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": [
          "technicalAndInteraction"
        ]
      },
      "id": "{40e4dba7-1502-49ac-afda-a4c9dc774e26}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://meet.google.com/*"
      ],
      "run_at": "document_idle",
      "css": [
        "content-scripts/content.css"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}