Help me: Djay for iPhone and Neural Mix

iOS and iPadOS

Hello everyone. How do I isolate the vocal of a song using Djay for iPhone and its new Neural Mix? Is this affordable? I installed but was unable to use Neural Mix. I don't understand about music, I'm totally a layman, I just want to isolate the vocal of my songs and save the final result in the Apple Archives application. I thank anyone who can help me.