1- When you log in to Spotify on another device, you will be asked what method you want to use to do so. You must select the option to use a PIN.
2- You will then be given an address to pair to pin. This address is www.spotify.com/pair.
3- You need to use another device to enter this address. After you open this address by your browser, you will be shown a multi-digit code. Enter this code on another device to which you want to connect to Spotify.
4- Then you will see the pairing of pins in Spotify. So this way you can get the PIN code and create a playlist of your favorite songs to listen to whenever needed.