Computer Configuration > Administrative Templates > Microsoft Edge > Kiosk Mode settings
Both
HKLM\Software\Policies\Microsoft\Edge
This policy only applies to Microsoft Edge kiosk mode while using the public browsing experience. If you enable or don't configure this policy, users can change the URL in the address bar. If you disable this policy, it prevents users from changing the URL in the address bar. For detailed information on configuring kiosk Mode, see https://go.microsoft.com/fwlink/?linkid=2137578.