Computer Configuration > Administrative Templates > Citrix Components > Citrix Workspace > User experience
Machine
HKLM\Software\Policies\Citrix\ICA Client\Engine\Sleep
Use this policy to configure the whether the client system and its display are allowed to enter power-saving (sleep) mode. When enabled, this policy controls whether the system and display are allowed to automatically enter sleep mode while a Citrix session is active. Enable 'Prevent system sleep' to prevent the system from sleeping while a session is active. Enable 'Prevent display sleep' to prevent the system's display from sleeping while a session is active.