Examine source code of Calendar Liberator

{
  "manifest_version": 3,
  "name": "Calendar Liberator",
  "version": "1.2.0",
  "description": "Export your Outlook Web calendar to an .ics file and import it into Google, Apple or any calendar app. Local, private, no sign-in.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "activeTab"
  ],
  "host_permissions": [
    "*://*.outlook.office.com/*",
    "*://*.outlook.office365.com/*",
    "*://*.office.com/*",
    "*://*.outlook.com/*",
    "*://*.live.com/*",
    "*://outlook.cloud.microsoft/*",
    "*://*.outlook.office.com.mcas.ms/*",
    "*://*.outlook.cloud.microsoft.mcas.ms/*",
    "*://*.outlook-sdf.office.com/*",
    "*://*.outlook-sdf.office365.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.outlook.office.com/*",
        "*://*.outlook.office365.com/*",
        "*://*.office.com/*",
        "*://*.outlook.com/*",
        "*://*.live.com/*",
        "*://outlook.cloud.microsoft/*",
        "*://*.outlook.office.com.mcas.ms/*",
        "*://*.outlook.cloud.microsoft.mcas.ms/*",
        "*://*.outlook-sdf.office.com/*",
        "*://*.outlook-sdf.office365.com/*"
      ],
      "js": [
        "ics-generator.js",
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "action": {
    "default_title": "Calendar Liberator - Export Outlook Calendar",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "96": "icons/icon-96.png",
      "128": "icons/icon-128.png"
    }
  },
  "author": "Fabio Biocchetti",
  "homepage_url": "https://github.com/fabiocchetti/calendar-liberator",
  "browser_specific_settings": {
    "gecko": {
      "id": "calendar-liberator@fabiocchetti.dev",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}