How can I use it from stock emacs ?

It seems all this package does is install and configure ada-ts-mode and eglot (to use ada-language-server) with some custom commands (defined in config.lisp). Here's how I adapted it to my config: https://pastes.io/ada-config

Note that I added a format-on-save hook in my config, and since I do completions using corfu and not company, I didn't include that part of the package.