I'm going to remove app form the app store but I need to provide bug fixes for existing users.
is there any way to continue to provide bug fixes to existing users even if the app is not available for download anymore on the Apple App Store?
Can't be done. I wish there was. I went through this a few years ago. I wanted to prevent new users from downloading the app but still provide bug fixes for existing users. The Apple app store doesn't support such a thing.