asdf.el is an Emacs interface for asdf version manager.
It provides functions that plug into the cli through Emacs and adds the necessary environment setup so your software will run within Emacs.
Add asdf.el to your load path and enable it.
(add-to-list 'load-path "/path/to/asdf.el")
(require 'asdf)
(asdf-enable) ;; This ensures Emacs has the correct paths to asdf shims and bin