Examine source code of Ortec work shifts export

{
  "description": "Download Ortec work shifts in iCalendar file format.",
  "manifest_version": 2,
  "name": "ortec-icalendar-shifts",
  "version": "1.3",
  "permissions": [
    "webRequest",
    "https://ess.ortecapps.com/*",
    "storage"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "225": "icons/ortec-inactive.png"
    },
    "default_title": "Download shifts",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "page": "background.html"
  },
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ac6deb52-465a-4e55-98e8-b3207e4875b0}"
    }
  }
}