Hello, Plengsak,
Thank you for contacting us and for using XStore.
We do not see the problem on your site right now, but we would recommend you downgrade PHP version to 7.x or 8.0, because your current 8.2.3 version is not fully supported yet. Contact your hosting provider to get assistance with it.
500 Internal server error means that there is some Fatal error in PHP script or on the server side. You can turn on debug mode in WordPress to see the error https://codex.wordpress.org/Debugging_in_WordPress
If it will not show any errors then contact your hosting providers and ask them to give you a server error log to check what is wrong.
Kind Regards,
8theme team