Computer Configuration > Administrative Templates > Microsoft Edge - Default Settings (users can override) > HTTP authentication
Both
HKLM\Software\Policies\Microsoft\Edge\Recommended
Indicates if Windows Credential UI should be used to respond to NTLM and Negotiate authentication challenges. If you disable this policy, a basic username and password prompt will be used to respond to NTLM and Negotiate challenges. If you enable or don't configure this policy, Windows Credential UI will be used.