Install Elixir on Ubuntu

Install dependencies

sudo apt install git curl libssl-dev automake autoconf libncurses5-dev

Install asdf version manager

Install erlang & elixir

asdf plugin add erlang https://github.com/asdf-vm/asdf-erlang.git
asdf plugin-add elixir https://github.com/asdf-vm/asdf-elixir.git
 
asdf install erlang latest
asdf install elixir latest
 
asdf global erlang latest
asdf global elixir latest

Install phoenix

mix archive.install hex phx_new