There are many platforms that provide copyrighted music purchase services. Each has its own merits.

First of all, you need to understand what your demands are.

What kind of music should I buy? Canned music? Vocal songs?

Where to use it, short video? Graduation project? advertise?

What style of music do you want? Is there anyone you can refer to?

What is the budget? Authorization period?

You can ask questions. Hope it will be adopted.