Not to be a party pooper or anything but Miss-Wanna-Die isn't JubyPhonic's original song. It's an English cover of a song called Shinitai-Chan (which is Japanese for I want to die-chan). The reason that I'm guessing JubyPhonic hasn't uploaded her cover of Shinitai-Chan is because of copyright reasons due to it not being an original song. Chances are if she tried to upload her cover, Himeringo (the artist of Shinitai-Chan) would take it down. Anyways that's just my assumption as to why Miss Wanna Die isn't on Spotify yet. Hope I cleared things up for you!!