It displays a searchable country dropdown with optional flags, country names, ISO country codes, and international phone codes.
The extension has many properties for customizing both the appearance and behavior of the input field.
More information:
https://www.wysiwygwebbuilder.com/countryselect.html
You can also download the extension via the Extension Manager:
Tools -> Extension Manager -> Online Gallery -> Forms
The extension is free for WYSIWYG Web Builder 21 users.
Please note: this extension is from my private collection and is provided “AS IS”.
Be sure to read the included documentation for setup and usage instructions.