Artstudio Pro funktioniert nicht

The successor to our famous ArtStudio app has been redesigned bringing many new features and improvements taking full advantage of the latest technologies Metal, iCloud Drive, Apple Pencil, and optimized for 64-bit multi-core processors to achieve the smoothest possible workflow.  We have implemented many parsers from the most popular assets/images formats and we are especially proud of our ABR/TPL parser which not only reads brush stamps and patterns, but also most settings which are converted to Artstudio Pro brush engine values.  Introducing Artstudio Pro, the most powerful painting and photo editing app available for both iOS and macOS.  Artstudio Pro introduces a new layer system with grouping, non-destructive layer effects, and adjustment layers.  Perfectly optimized, lag free mechanism generating smooth, real looking strokes, making the most of Apple Pencil.  It allows working with multiple documents, supports large canvas sizes and an unlimited number of layers.  The powerful GPU accelerated ArtEngine developed by Lucky Clan is 5-10 times faster than the previous engine.  Photo editing options developed in cooperation with professional photographers.  Incredible optimization ensures smooth work even with large canvases.  Each feature was tested in several scenarios and light conditions.  Artstudio Pro for iOS requires iPhone or iPad running iOS 15.