Computer Configuration > Administrative Templates > Microsoft Edge
Both
HKLM\Software\Policies\Microsoft\Edge
OBSOLETE: This policy is obsolete and doesn't work after Microsoft Edge 138. This policy provides a temporary opt-out for the new keyboard focusable scrollers behavior. When this policy is Enabled or unset, scrollers without focusable children are keyboard focusable by default. When this policy is Disabled, scrollers aren't keyboard focusable by default. This policy is a temporary workaround. Starting in Microsoft Edge version 139, this policy is obsolete.