I know you can install RPMs using URLs, for example
rpm -i http://mirror.alpha-labs.net/centos/7/os/x86_64/Packages/rpm-4.11.3-40.el7.x86_64.rpm
However, this URL is for CentOS 7.
What URL "prefix" should be used for RedHat 8 x86_64?
I am not sure why you are trying to download a package manually -- normally you would install packages from repositories using
yum). But if you really need to manually download a package, for CentOS 8 Stream you can just pick a mirror from the CentOS mirror list, for example
http://ftp.cvut.cz/centos/8-stream/ and then the URL depends on which repository the package is. For the
rpm package which is in the
BaseOS repository the full URL would be
But these are repositories for CentOS, not RHEL. RHEL repositories are not public, you need subscription to access RHEL repositories and you need to register your system using the subscription manager.