You can integrate Shopping with Microsoft Store for Business so that users can request applications that originated on Microsoft Store for Business just like any other applications.

You have two options to enable Shopping integration for Store for Business:

  1. Enable Shopping's Intune Integration, in which case Store for Business applications can be made available in Intune and then added to Shopping
  2. Enable Configuration Manager's Store for Business integration, in which case Store for Business applications are available in ConfigMgr just like any other applications and thus can be made available in Shopping

Neither solution is full Store for Business integration in the sense of providing license management or automatic updating of Store for Business apps. But both allow your users to shop for Store for Business apps.

To enable Intune's Store for Business integration, follow the Microsoft documentation: https://docs.microsoft.com/en-us/mem/intune/apps/windows-store-for-business

To enable the ConfigMgr's Store for Business integration, follow the Microsoft documentation to:

With those two steps done you can then add the apps to Shopping the same as any other ConfigMgr applications.

The ConfigMgr support for Microsoft Store for Business apps is limited, as per the Microsoft documentation. You will likely get the most benefit from free offline licensed applications since you will not need to manage costs and users can use the applications in any location.