That’s because, out of the box, Server 2012 R2 is running PowerShell 4.0. These Gallery cmdlets require PowerShell 5. To upgrade, you either need to upgrade to PowerShell 5.0 and that means installing Windows Management Framework 5.0. This is compatible with versions of Windows as far back as Windows 7, and Windows Server as far back as 2008 R2. Anything earlier, and you’re out of luck. This also requires the .NET framework 4.5 (or above). That means system updates, which could (potentially) lead to system reboots. Plan (and for the love God test) accordingly!
There’s a couple other hitches as well. One, and this sort of goes without saying, you need internet access for this to work. If your machines are behind any kind of filtering or firewall restrictions that prevent them from talking out to the internet, you’ll need to either open them up or use the Save-Module feature to download the bits and install them yourself. Secondly, you need Administrator access for this to work. And three, if you do install them manually, you might have different versions installed for different users (or service accounts).
They’ve made it nice and easy, so read Drew’s post and give it a try.