To install an MSIX package for all users via PowerShell, you must use provisioning. Standard commands like Add-AppxPackage only install the application for the current user. To make an app available to every user on a machine (existing and future), you must register it at the system level. Understanding MSIX "All Users" Installation
To confirm that the package has been successfully provisioned for the system, run: powershell install msix powershell all users
Removal (if needed):
All-users MSIX installs live under %ProgramFiles%\WindowsApps. But by default, this folder is hidden and locked. To see it: To install an MSIX package for all users