How do I use the NanoServer Docker image?

MSFT appear not to have updated their documentation on Nano Server since 2017 and all information appears to be wrong or out-of-date.

All documentation I can find refers either to the NanoServerPackage module last updated in 2016 (which doesn’t work) or to the NanoServer packages being on the ISO.

There are no Nano Server packages on the Server 2019 ISO that I can find. (Apparently they were on the 2016 ISO.)

I found mention of a NanoServerPackage PowerShell module.

The NanoServerPackage module cmdlets don’t work for me:

PS C:\Users\user\Documents> Find-NanoServerPackage
WARNING: Cannot find path ‘C:\Users\user\AppData\Local\NanoServerPackageProvider\searchNanoPackageIndex.txt’
because it does not exist.
WARNING: Save-HTTPItem: Bits Transfer failed. Job State: ExitCode = -2147023651

Does anyone know how I am supposed to install, for example, IIS on a NanoServer Docker image?