Hey uhh, did i do something wrong between downloading it, putting it in and starting it?
For all the people attempting to pair spotifive through a localhost server, it will not work. However, as long as you have your server accessible outside of your own pc, you can just connect through server link. Specific instructions: Open FiveM → Press Play (Don’t press localhost) → search for your server → connect to your server → Pair spotifive. That should work 
Are you able to change songs and such in the server? not seeing any options for that
having the same issue. I was able to connect it and it recognizes i have spotify premium, however media controls were not working for me (Holding alt). Also, I am not sure if you are supposed to have the spotify app running and playing the songs or FiveM will have the songs playing in the game because it is not playing any songs in the game for me, only showing the UI in the bottom but not actually playing the songs.
its meant to work as a controller, as opposed to a player. theres no easy (or feasable, as the one api i tried didnt even seem to work in nui) way to have spotify audio playing through the client
will no longer be supporting this resource, if people want to use it and recreate it/modify it, feel free as long as you let me know about it first, as i find it stressful ensuring stuff like this stays running.