First need install erlang-elixir-mix properly
Now you will need a global installation of mix dialyxir.
{:dialyxir, "~> 1.0.0-rc.2", runtime: false}
After install successfully dialyxir globally you simple need install this gem
gem install pronto-dialyxir
After the gem is installed, Pronto will already detect dialyxir runner inside a elixir project.
You can configure in mix.exs