Examine source code of Week Number

{
  "manifest_version": 3,
  "name": "Week Number",
  "version": "1.0.0",
  "description": "Show the current ISO week number, day of year, and other calendar information.",
  "browser_specific_settings": {
    "gecko": {
      "id": "weeknum6w@toolbox.example",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "Week Number"
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png"
  }
}