Examine source code of Citace PRO

{
  "name": "__MSG_title__",
  "description": "__MSG_description__",
  "author": "Citace.com, s.r.o.",
  "version": "3.1.5",
  "permissions": [
    "activeTab",
    "clipboardWrite",
    "scripting",
    "storage"
  ],
  "default_locale": "cs",
  "host_permissions": [
    "https://www.citacepro.com/*"
  ],
  "action": {
    "default_title": "__MSG_title__",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "firefox@citacepro.com"
    }
  },
  "manifest_version": 3
}