How can you install Drupal CMS without Composer?

Hi all; forgive my ignorance here, but how can I install Drupal / Drupal CMS without using composer. I am using Siteground for my web host, and their software installer is a few versions behind. I don't believe I have access to composer through their platform to install the CMS platform, and im not really interested in leaving Siteground as they host all my other sites.