Need help making music that can be changed only by admins

So, I need help making a music system where only authorized admins can change the id of the music, it has to be local, and start once the player is loaded so they hear the start of the music when they join, the music stays the same if you reset, i got everything but the change id part, how would i be able to change the id? this is what i got right now
Screenshot 2024-08-15 115532