Examine source code of Clean Copy

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "Clean Copy",
  "version": "1.1.0",
  "description": "Copy selected text as plain text.",
  "action": {
    "default_title": "Clean Copy",
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab",
    "scripting",
    "contextMenus"
  ],
  "background": {
    "service_worker": "background.js"
  },
  "options_page": "options.html",
  "commands": {
    "clean-copy": {
      "suggested_key": {
        "default": "Ctrl+Shift+Y",
        "mac": "Command+Shift+Y"
      },
      "description": "Copy selected text as plain text"
    }
  }
}