How to raise 2 sites on Apache server?

Question

linux

Hello. raised the site on the sait.by server, I need to make a 2 site with a 3-level domain mail.sait.by,
the sites are in the directories /var/www/html/sait.by and /var/www/html/mail.sait.by for
some reason then when I go to a particular site, it opens a folder with sites
sait.by works with SSl I pass
the settings through Webmin,
help me deal with this problem

Answer 1

Create virtual hosts, depending on the distribution, the creation process may vary. It is better to do everything manually through the configs, I do not recommend using graphical installers.

Answer 2

By the fact that you need to create a virtual host. Apache is not configured.
It is a pity that Webmin used 10 years ago)))

for some reason, when I go to a particular site, it opens a folder with sites

You are running Apache only with a defaul host, so any request most likely goes to /var/www/html/ and folder browsing is enabled there (folders and files are displayed as in explorer).
You need to create a virtual host with the name sait.by (here is a subtlety - how to say it right?) And the root folder /var/www/html/sait.by/. Repeat with mail.sait.by.