Hi there
running a W2K16 server as a VM - seems the the optional features install don't include the openSSH server or client -- I'm using the Desktop experience standard edition of W2K16 server

However using the powershell command from within the VM both products get installed easily enough :

# Install the OpenSSH Client
Add-WindowsCapability -Online -Name OpenSSH.Client~~~~0.0.1.0

You should see this Path :
Online : True
RestartNeeded : False

For OPENSSH server (you need this if Windows is to be able to SEND files via sftp etc etc)

# Install the OpenSSH Server
Add-WindowsCapability -Online -Name OpenSSH.Server~~~~0.0.1.0

Again you should see this

Path :
Online : True
RestartNeeded : False

Whether or not the product is available via the "add optional features" might depend on edition and DVD image of your server -- there's a whole slew of optional editions for W2K16 server. (W2K19 server is simpler in that regard but is still missing bits and pieces if you are trying to use these servers as desktops). They run nice and fast though as VM's !!

Cheers
jimbo