If you've installed iTunes 12.7 on your computer you won't, app are not part of iTunes 12.7, management of them is now done directly on each iOS device.
iTunes 12.7 changes : Changes in the new iTunes - Apple Support
You can add an app's .ipa file from your computer (e.g. if an app is no longer in the store for redownloading or if you want an older version) to the iPad by dragging-and-dropping from Windows Explorer / Finder onto the device in iTunes - see towards the bottom of this page : Manually manage content on your iPhone, iPad, or iPod touch using iTunes - Apple Support
Or you could install iTunes 12.6.3 instead (it's aimed at businesses who have to deploy apps, but works for individuals as well) : Deploy apps in a business environment with iTunes - Apple Support