Can be done through GPO

ComputerPoplicy > Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Session Time Limits > set values as follows:  
Set time limit for disconnected sessions: Enabled  5 minutes  
Set time limit for active but idle Remote Desktop Services sessions: Enabled  5minutes

references:

Logoff Idle Users | Microsoft Learn How can I log users off after a period of inactivity, rather than merely locking the workstation? Is there a “logoff” screen saver? - The Old New Thing (microsoft.com)