How to use vault repo on 9.0

I’ve been asked to use 9.0 to track long term releases rather than starting on 9.1. I need kernel-devel package, but the version dnf sees is for an updated kernel likely for 9.1. I see in the vault repo web interface that there is the legacy version, but when I look in /etc/yum and /etc/dnf, I don’t see any way to lock or point the search to the vault to get the actual packages, the dirs just look empty. Any pointers on getting packages installed directly for 9.0 would be appreciated.
Thank you,

Such “branching” is only supported by upstream (RHEL). Rocky does only support the latest branch (9.1 for now). The vault repo is just an archive for history reasons. So, someone should not deploy systems from the vault repo - its just not secure anymore.

Thank you for your reply.