Hi
I enabled debug mode and realized that the error comes from 3rd party extension of your site:
JROOT/joobi/node/library/class/table.php:415
2 require_once() JROOT/joobi/node/api/addon/joomla30/joomla30.php:1216
3 WApplication_joomla30::make() JROOT/joobi/entry.php:31
I'm not sure which 'joobi' is, so kindly check with its provider to make sure that it's ready for PHP 8 too.