Examine source code of Numbers Formatter

{
  "manifest_version": 3,
  "name": "Numbers Formatter",
  "version": "1.1.0",
  "description": "Dedup numbers, mask last 3 digits, copy to clipboard.",
  "permissions": [
    "storage",
    "clipboardWrite"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "Numbers Formatter"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "numbers-formatter@local",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}