As of now, Genshinimpact is not available on macOS official App Store. There is an option for developers to restrict their apps from running on ARM Macs. This means they won’t show up under iPad and iPhone apps section.
You can however try this method for side loading iOS apps : Here’s howto run any iOS app you own on Apple’s new M1 Macs. This covers nearly all apps whether or not officially supported. However, be wary that this method is likely to not have keyboard controls. You might have to use cursor to use on screen controls.
Second option is using Android emulators like Bluestacks for running android version of Genshinimpact.