Building a music application using an API

Hello everyone, my name is Joshua Osagie. For 2 months now, I have been trying to build my own music application, but unfortunately, I can’t because I was thinking I would get an API from maybe Apple Music or Spotify that will grant me access to over 100 million music. Even if the API is paid for, I have been doing my research, but then it's kind of impossible. So please, if anyone has an idea on what I can do to bring this application to life, I will really appreciate it. Or if anyone could share me an idea on how to get over millions of music on my app, I will be really grateful.