Upstream URL to sync a file repository?

I created a repository of type file in Foreman. Trying to understand what kind of service “Upstream URL” expects?
I have several local rpm repositories for internal distribution of rpm packages built with the “createrepo” command in Linux but I am trying to understand what I need to do for a file repository.
I assume “createrepo” is for rpm packages only? Maybe just create a simple https site and add files to a directory that is accessible from Foreman?

See Managing Content

Thanks, tried to search for the documentation but obviously failed!
Feels like it would help to have search feature on the page.

Trying to figure out what kind of access control I can set for file repositories. Any host now seems to be able to access any files in these repositories. Is that what the SSL settings are used for?
SSL Client Cert
SSL Client Key

Or is it expected to use content views to restrict access to file repositories for hosts?

It‘s a repository like any other type. Same rules apply.

And just like any other repository the SSL certificate settings are used to access the URL if it‘s https, if you want to verify the connection or need client authentication to get access.