I had set this up on my server systems a long time ago and forgot the details.
I read this: Changes/SwapOnZRAM - Fedora Project Wiki
that told me that the default config in installed from package zram-generator-defaults.
That consists of one file /usr/lib/systemd/zram-generator.conf.
In that file it tells you where to config in /etc.
See if that gets you going.