Lz4 & RHEL8 - where does it "come from"

we have our own repos on a foreman server, synced from various public repos monthly.

but what we are using doesn't provide lz4 - "yum install lz4" just returns
"No match for argument: lz4"

the public repositories configured/used (previous administrator, no documentation :-/ )

https://dl.fedoraproject.org/pub/epel/8/Everything/x86_64/
https://cdn.redhat.com/content/dist/rhel8/8/x86_64/appstream/os
https://cdn.redhat.com/content/dist/rhel8/8/x86_64/baseos/os
http://rpms.remirepo.net/enterprise/8/safe/x86_64/

( FWIW those cdn.redhat.com repos don't sync any longer - the error with a 403, and that's born out by trying a curl -k on them )

So what public repo should we be using for Base OS rpms, given that
https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/8/html/package_manifest/baseos-repository#BaseOS-repository

suggests that the Base OS repository DOES include lz4 ?

cheers

didds