Certain of our clients need to install apps on their own when they receive our iPads, and sometimes for bigger apps such as PowerPoint, it can be way faster to bulk install apps onto multiple iPads using either Apple Configurator or using iTunes, which is a more universal option for most people. 

However, Apple has removed the app installation functionality in the latest iTunes update, which can really disrupt certain business users. According to Apple:

Apple offers Volume Purchase Programs and Apple Configurator on Mac to help enterprise environments manage and mass-deploy apps on iOS devices. But certain business partners might still need to use iTunes to install apps.
 

Fortunately, Apple as released a special version of iTunes which restores this removed functionality. To download it for your Mac or PC, visit

https://support.apple.com/en-us/HT208079

If you've already installed a newer version of iTunes, you can download this version of iTunes on your Mac, PC 32-bit or PC 64-bit* and run the installer. After installation is complete, you can continue to deploy apps with iTunes.

You won’t be prompted to download new versions of iTunes after you install this version. Manually update to the latest version of iTunes when you're ready to upgrade.