Examine source code of C counter

{
  "manifest_version": 3,
  "version": "1.3.0",
  "name": "C counter",
  "action": {
    "default_popup": "index.html",
    "default_icon": "icon-192.png"
  },
  "permissions": [
    "clipboardWrite"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "c-counter@lukadjo.t.me",
      "strict_min_version": "109.0"
    }
  }
}