how to turn off Cloud Music Library.

On your iPhone, iPad, or iPod touch

1. Go to Settings > Music.
2. Turn Off Sync Library. If you don't subscribe to Apple Music or iTunes Match, you won’t see an option to turn on / off Sync Library.

If Sync Library is updating or turned off, you'll see a message at the top of the Library tab in the Apple Music app.

On iOS 12

1. Go to Settings > Music.
2. Turn Off iCloud Music Library. If you don't subscribe to Apple Music, you won’t see an option to turn on / off iCloud Music Library.

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you.