Iphone apps
Why am I unable to see my apps from my phone on iTunes when I sync my phone?
iPhone 6, iOS 12
App management was removed from iTunes several years ago with iTunes 12.7.
If you need to maintain access to apps, then you'll need to download and install the out of sequence version that still supports them. Last version to still support apps is iTunes 12.6.3.5.
See here: Managing apps with iTunes 12.7 or later - Apple Community
and here: Deploy apps in a business environment with iTunes - Apple Support