Computer Configuration > Administrative Templates > Microsoft Edge
Both
HKLM\Software\Policies\Microsoft\Edge
OBSOLETE: This policy is obsolete and doesn't work after Microsoft Edge 96. Support for AppCache and this policy was removed from Microsoft Edge starting in version 97. If you set this policy to true, the AppCache is enabled, even when AppCache in Microsoft Edge is not available by default. If you set this policy to false, or don't set it, AppCache will follow Microsoft Edge's defaults.