Edition:The MSIX project type is available in the InstallShield Premiere and InstallShield.
MSIX is the Windows app package format that provides a modern packaging experience to all Windows apps. The MSIX package format preserves the functionality of existing app packages and/or install files in addition to enabling new, modern packaging and deployment features to Win32, WPF, and WinForm apps.
In InstallShield 2019 and later, you can now use MSIX project type to build MSIX packages. It contains windows applications for side-loading or distribution via the Windows Store.