Computer Configuration > Administrative Templates > Microsoft Edge > Related Website Sets Settings
Both
HKLM\Software\Policies\Microsoft\Edge
This policy lets you control the enablement of the Related Website Sets feature. Related Website Sets (RWS) is a way for an organisation to declare relationships among sites, so that Microsoft Edge allows limited third-party cookie access for specific purposes across those sites. If this policy set to True or unset, the Related Website Sets feature is enabled. If this policy is set to False, the Related Website Sets feature is disabled.