Now supporting Zen Cart 2.1.0 and above, released as a Zen Cart encapsulated plugin. Validated on PHP versions 8.0 through 8.3.
For additional questions and documentation, please see the plugin's readme.html.
Zen Cart Plugin Download: https://www.zen-cart.com/downloads.php?do=file&id=2164
Zen Cart Support Thread: https://www.zen-cart.com/showthread.php?223003-VAT4EU-Support-Thread