Retrieve group details for planner using client side

blitz2384 you can use the Graph API - that can be called via PowerShell - the 'owner' of a Plan will be the Group GUID - then you can use that GUID to get whichever other details of the group you require.  The Graph API can be found here for Planner - Use the Planner REST API - Microsoft Graph v1.0 | Microsoft Docs and to use Graph via PowerShell see Get started with the Microsoft Graph PowerShell SDK - Microsoft Graph | Microsoft Docs

Best regards,

Brian