Spotify client without Authorization Code flow

in Spotify's web API it is mentioned that one can't request private data or do any action that requires a specific scope if he uses the Client Credentials authroization flow which requires only client_id and client_secret and can only access scopes through Authorization Code flow where he/she's gonna have to set up a website and a callback url to first get a code then do multiple things and can't only rely on client_id and client_secret to access scopes but i have seen projects on github like this one https://github.com/jedruniu/spotify-cli which only use the client_id and client_secret to do actions that require some of those scopes how does that project for example use only client id and secret to do that i have been confused about this for a few days