therubyracer and libv8 error on Ubuntu and Macos

[senolatac]

Here is the project and github-action: https://github.com/senolatac/cuttlefish-email-sender/actions

And examined and tried to fixed with previous suggestions: Cannot install therubyracer on Ubuntu 20.04 but no chance yet. Or another one: libv8 required python 2 to be installed in order to build - Windows

Error says:

/usr/local/bundle/gems/libv8-3.16.14.19/ext/libv8/builder.rb:86:in
`setup_python!': libv8 requires python 2 to be installed in order to build, but
it is currently not available (RuntimeError)...

When I add this line: gem install libv8 -v '3.16.14.1' -- --with-system-v8 it gives error on therubyracer. When I try to add this line gem install therubyracer -v '0.12.3' -- --with-system-v8 it couldn't find v8.

Any suggestion?

BTW: it works on Windows but not on Ubuntu and MacOS