Intelligent Communications takes the next step with calling in Teams

Unfortunately I'm not as well-versed in PowerShell as I probably should be for this. PowerShell is both a blessing and a curse in that I completely see the power it can yield, but not knowing exactly how to use it makes it very cumbersome at the moment, and most instructions on how to use it pretty much assume you know the basics (which I don't, unfortunately). With that said, I was able to get Teams to start ringing for inbound calls with https://docs.microsoft.com/en-us/MicrosoftTeams/configuring-teams-calling-quickstartguide. However, when I go to run the following command to get the option to set the "Preferred calling application", I get an error (both listed below):

Command:

New-CsTeamsInteropPolicy -PolicyName tag:CustomPolicy -AllowEndUserClientOverride:$True -CallingDefaultClient:Default -ChatDefaultClient:Default

Error:

New-CsTeamsInteropPolicy : The term 'New-CsTeamsInteropPolicy' is not recognized as the name of a cmdlet, function,
script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is
correct and try again.
At line:1 char:1
+ New-CsTeamsInteropPolicy -PolicyName tag:CustomPolicy -AllowEndUserCl ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (New-CsTeamsInteropPolicy:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

While I wish it were as simple as going into an administration panel, for now it is what it is. Does anyone know how I can get past this in order to create and apply the custom Teams interop policy?