I coipied the code from this page but cannot get the line
PackageUpdateAvailabilityResult result = await package.CheckUpdateAvailabilityAsync();
to work. VS keeps saying

Also I had to change the AddPackageByAppInstallerOptions.ForceApplicationShutdown into AddPackageByAppInstallerOptions.ForceTargetAppShutdown but the first thing I cannot fix?
What is going on here.
P.S. Iused the winmd file from the Program Files (x86)\Windows Kits\10\UnionMetadata\10.0.26100.0\Windows.winmd
I coipied the code from this page but cannot get the line
to work. VS keeps saying

Also I had to change the
AddPackageByAppInstallerOptions.ForceApplicationShutdownintoAddPackageByAppInstallerOptions.ForceTargetAppShutdownbut the first thing I cannot fix?What is going on here.
P.S. Iused the winmd file from the
Program Files (x86)\Windows Kits\10\UnionMetadata\10.0.26100.0\Windows.winmd