PowerShell command to list individual drive usage in a pool in Storage Spaces

Is there a powershell command to list the disks in a pool and how much of the drive is being used?
The GUI in Windows 10 shows this information but I can’t find a way to get it via powershell.
Basically I’m looking to add some monitoring to tell me when I might need to optimize the disk usage.
This lists all the disks in the pool and their size but not how full they are.

Get-PhysicalDisk -StoragePool (Get-StoragePool -FriendlyName "MyPool")