I got these instructions from the quickinstall options list here: Foreman :: Manual , and also this post: Change Foreman web SSL certificate - #17 by romgo
I didn’t see anywhere in the EL8 documentation about using custom certs. It looks like the installer options are named quite a bit different for non-katello installer. I’m really wondering at this point if we should have just installed Katello. But already quite a few hosts registered that we are managing, so would somehow have to backup/restore all those.