Currently, the program requires a .env file which you will have to get from a spotify app, and install all the dependenceis via npm install.
In addition, the playlist can only have a maximum of 100 songs and must be set to public.
Inspired from a video by gabi belle on Why Spotify Playlists Never Truly Shuffle
There are many useful datas I am collecting which I am directly using Spotify API for. For example, for Artist, for Track, Track Audio Anaylsis and Track's feature, for Album and for Playlist.
I have also used the following website to further the study on how to shuffle songs effectively.