Homebrew does not keep older versions for all of their packages. Elixir is one of those where there aren’t older versions. You can look for older packages like this: brew search [packagename]. If there are older versions, they’ll pop up.

So for change the version it’s needed to use a manager?
I already have installed with brew and for use diferent versions I install right now the asdf.
It’s very simple this manager and I liked.
My question is, I need to uninstall the elixir and Erlang with homebrew?
Or just keep them? Because I know it’s a lot capacity keep them.

Thanks folks, I’ll give a shot at kiex then.