What system to choose for publishing the results of work to customers on the site?

Question

CMS

There is a need to post files for customers on the site. To give a link, and then the customer went in and downloaded the file. It is necessary that a username and password be requested to download the file. Or for downloading each file your own password, or for each customer your own login-password. The system needs to be hosted on your website, cloud solutions will not work. It is desirable that the system be free, as well as easy to install and use. That is, Confluence, for example, will not work at all.

Answer 1

Set up FTP access. Each customer has their own folder for files.

Answer 2

If cloud services are not suitable, then upload the file to the site itself.
And add the file to the archive with a password)
There is a second option, use almost any cms, which usually hides texts from unauthorized users, but I don’t think you should use a whole cms to solve one problem! It is better to dig aside how to hide content from unauthorized users)