For instructions on how to use this repository, consult the official docs.
You should be good to enable the copr repository and then install a package from it.
$ dnf -y install --skip-broken 'dnf-command(copr)' 'dnf5-command(copr)'
$ dnf -y copr enable @fedora-llvm-team/llvm-snapshots
Then install clang or some of the other packages.