Universal purchase allows customers to purchase your related iOS, macOS, and tvOS apps together in the App Store. To offer your app as a universal purchase, create one app record in App Store Connect and select the platforms. Then associate each platform-specific build to that app record. The apps share the same bundle ID, but information specific to each platform can be added separately.
To learn more about universal purchase, go to Add a platform to create a universal purchase in App Store Connect Help.