We have detected that your server is using PHP 7.4.8 which is obsolete and no longer receives official security updates by its developers. The Joomla! Project recommends upgrading your site to PHP 8.0 or later which will receive security updates at least until 2023-11-26.
Please ask your host to make PHP 8.0 or a later version the default version for your site. If your host is already PHP 8.0 ready please enable PHP 8.0 on your site’s root and ‘administrator’ directories – typically you can do this yourself through a tool in your hosting control panel, but it’s best to ask your host if you are unsure.
Joomla installation requires new PHP version 8
(other information and details relevant to your question)