Hi David,
After importing the MP, the option will be available. I think the MP you mentioned is as below:
https://gallery.technet.microsoft.com/Sample-Management-Pack-17b76379
Unfortunately, the link is broken. if you need create a powershell based monitor, you can check this one:
https://github.com/squaredup/Community.PowerShellMonitoring.MP
Regards,
Alex