Examine source code of Timestamp Converter

{
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "{2d39e24e-4ae5-4185-8fd6-0e6eea714228}",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "1.3.3",
  "default_locale": "en",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "background": {
    "service_worker": "js/background.js",
    "scripts": [
      "js/browser-polyfill.js",
      "js/background.js",
      "js/functions.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/browser-polyfill.js",
        "js/content.js"
      ],
      "all_frames": true
    }
  ],
  "permissions": [
    "contextMenus",
    "clipboardWrite",
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "__MSG_extensionName__"
  }
}