The Apple App Store varies significantly by region. In some countries, specific applications may be unavailable or delayed in release due to local laws or distribution agreements. An IPA file allows a user to install an application that exists in the store but is not visible in their local region.
TrollStore is a permanent sideloading utility that uses a CoreTrust bug to install unsigned IPAs. It works on specific iOS versions. virtual+dj+remote+ipa
Because Apple does not allow direct installation of arbitrary IPAs without signing, you have three pathways: The Apple App Store varies significantly by region