Can there be some simple code will be able to increase an .htaccess file or my virtual host file to enforce http fundamental auth?

How about this ?

AuthUserFile /my/derectory/.htpasswd
Require valid-user
AuthName "Secured Access"
AuthType Basic

the interesting part for you personally is Require valid-user

But when you are able to, please provide more informations about how you get you attempted to complete ^^